- "You know what your punishment is Leonard? You end up being a better man. And, so do I."
- "Better? You mean softer"
"No. I mean better"
- —Mick talking to Leonard about his future[src]
Leonard "Lenny" Snart (born June 2, 1972- died in the Vanishing Point), nicknamed Captain Cold (or simply Cold) by Cisco Ramon, was a world-class thief from Central City. He was also the older brother of Lisa Snart and the son of the late Lewis Snart.
In 2014 after the appearance of Barry Allen/The Flash, who started endangering his heists with his heroics, Leonard sought to eliminate him. Acquiring the cold gun he had frequent encounters with the Flash, along with his partner Mick Rory/Heat Wave. In 2015 Snart and Barry reached a truce where Barry would let Snart continue his heists, so long as he didn't kill anyone in the process and didn't expose his identity to anyone and became an occasional ally of his.
In early 2016 Snart and Mick were recruited by Rip Hunter into the Legends, a time travelling team of superheroes dedicated to hunting down Vandal Savage and preventing his uprising in 2166. Being considered "supervillains" he and Mick were seen as outcasts. Though both initially joined to exploit the potentials of time travel Snart came to be genuine about the cause, and genuinely befriended the Legends. He also became close with Sara Lance/White Canary and developed a romantic interest in her. However Snart's change of heart led to a falling out between him and Mick. Following Mick's betrayal of the team, allying with time pirates to save himself, Snart was forced to maroon him in time which indirectly led to him becoming Chronos. After talking sense into Mick they continued the Legends mission together. When the Legends were in danger of being killed by the Time Masters in the Vanishing Point, after learning they were in league with Savage, Snart sacrificed himself to save his friends and destroy the Time Masters, ending their corruption. He also shared a kiss with Sara before he sacrificed himself. Leonard's death was avenged when the Legends finally killed Savage.
A year after his death a younger version of Leonard from 2014, prior to joining the Legends, was pulled from the timeline by Eobard Thawne/Reverse-Flash and recruited into the Legion of Doom to aid in their quest to retrieve the Spear of Destiny. After Eobard Thawne was erased from existence, Snart was returned back from where he had been plucked from history where Mick then erased his memory to keep his place in time intact.
Original timeline: In 1975, Leonard's father was arrested for attempting to steal the Maximilian Emerald, causing him to be sent to jail for 5 years.
Altered timeline: In 1975, Leonard went downstairs to get a glass of water, but, inadvertently he meet his older self from 2016, in which he thought he was a friend of his father. His older self advise him to never let anyone hurt him, but, later his father appeared and sent him upstairs. In the next day, his father was arrested for attempting to sell the Emerald to an undercover police officer.
When his father was released, he began to take his anger out on Leonard. His sister, Lisa, was soon born and was equally abused. Lewis turned to crime, mostly breaking and entering, bringing his young son along so that he could help him to disable the security systems during the heists. Sometime later, Lewis was sent to prison. Leonard's grandfather took him and his sister to a diner right across from Central City Precinct named the Motorcar. Snart kept going there in his later life to listen to police radios and learn their response times. While Lewis did frequent sentences in and out of prison, Leonard mostly raised Lisa himself and thus shares an almost parental bond with her, despite their vastly different personalities.
While in juvenile detention at the age of 14, Snart was jumped by several guys and almost stabbed with a shiv until Mick Rory intervened and defended the scrawny teenager, the two forming a close partnership.He dropped out of high school and eventually became a bank robber, putting together a crew. Every six months or so, he arrived in Central City to case a job for a few weeks, and disappeared after stealing his target. He became one of Central City's Most Wanted. He worked on a job with Rory, which ended badly for the latter. Snart ended the partnership between the two when Rory lost control of his pyromania while on a job, burning down the building they were inside of. Snart escaped without injury while Rory received severe burns.
Confronting Sam Scudder
On the night of the S.T.A.R. Labs particle accelerator explosion, Snart confronted Scudder and Dillon with two of his men. Scudder said that without them "He would still be kicking down liquor stores", but Snart told him that his version of reality is warped. When Scudder told him that he doesn't care about his rules and that no one in Central City can stop them, Snart realized that they don't want to be in his crew anymore. When the two confirmed his suspicion, Snart pointed a gun on Scudder. However, Scudder disarmed Snart and the two began to fight, while Dillon fought Snart's men. At the end, Snart successfully beat Scudder and was about the shoot him. However, when the S.T.A.R. Labs particle accelerator exploded, Snart told his men to run. He ran from the place, but like everyone else in Central City, he was hit by the wave from the particle accelerator. However, he want not affected by it. After that encounter, Snart never saw Scudder and Dillon again. 
Upping his game
Kahndaq Dynasty Diamond heist
In 2014, Snart and his crew attempted to hijack an armored car in order to steal the Kahndaq Dynasty Diamond it was carrying to an exhibition in the Central City Museum. They stopped the armored car by hooking it to the tow truck they brought to the robbery via steel cables. After taking the security guards as hostages, Snart opened the door of the armored car by using liquid nitrogen on it, just before the Flash arrived. The Flash quickly took down the robbers, making Snart lower his mask and expose his face. One of the security guards was shot in the shoulder by one of Snart's men, forcing the Flash to take him to a hospital as Snart and his crew escaped.
Back at their base of operations, Snart looked at the camera footage of the robbery he stole from the armored car as his men argued about what the Flash was, with one of them stating that maybe it was a top-secret drone. Snart explained that they attacked moving targets because the police response time was a hundred eighty two seconds once the armored car reported the robbery, as opposed to sixty seconds with banks. He berated his man who shot the security guard for "losing his cool" when the Flash had arrived. When the man said he was quitting, Snart killed him, stating that "when you're out, you're out." He claimed that the Flash was a man, and they needed to "up their game."
Snart later met with the arms dealer Basil Nurblin. Nurblin first offered Snart a fire-based weapon, but he refused, saying "he did not need to heat things up, but slow them down." Next, Snart looked at a weapon stolen from the S.T.A.R. Labs that emitted a cold substance and glasses meant to protect against the glare the weapon caused. Snart asked Nurblin who else knew he had taken the weapon, and when Nurblin answered they were the only two, Snart shot and killed him with his newly acquired weapon.
After obtaining his cold gun, Snart went to the Central City Museum to observe the security around the diamond he had tried to steal earlier. By taking the exhibit tour twice, he alerted the museum owner Dexter Myles, who contacted Detective Joe West, who followed Snart after he left the museum. When Joe caught up to him, Snart used the cold gun to freeze the road underneath a newly arriving police car and escaped into a nearby theater as the car crashed. Inside, Snart shot at Detective West, but the Flash got there in time to throw the detective out of the way, instead being hit by the weapon himself. Snart then started shooting at the nearby civilians as a test run, forcing the Flash to save them. The Flash saved all but one of the civilians; he was unable to get to the theater's security guard in time as he was slowed down by the cold gun. Snart left the scene when the Flash was distracted by the deceased security guard.
Returning to his base, Snart told his two remaining men that they would be back to the museum to steal the diamond that night. When his men protested, saying the museum would be crawling with the police and the Flash, Snart answered that his cold gun could stop the Flash and he knew the Flash's real weakness. His men mutinied and pulled a gun to his head. They left, saying that Central City was no longer Snart's playground now that the Flash was there. Disagreeing, Snart went to the museum by himself and broke in using the cold gun. He stole the diamond and made his way to the Central City Train Station, where he was engaged in a gunfight with Detectives West and Eddie Thawne. Snart escaped the two men by getting on a train, but this time he was challenged by the Flash, who had followed him using a signal the cold gun emitted. He told the Flash that he had seen his real weakness during the armored car robbery and at the theater. Explaining that he would save himself while the Flash saved everyone else, he shot the floor of the train with the cold gun and jumped from the train before it was derailed. The Flash got everyone out of the train but was ambushed by Snart, who shot him in the back with the cold gun. He thanked the Flash for forcing him to up his game, then was threatened by Cisco Ramon with what he claimed was a prototype of the cold gun but was actually just a vacuum cleaner with LED lights. When Ramon called him Captain Cold, he smiled and left, taking the diamond with him.
Snart discovered and disabled the signal his gun emitted with which the Flash had tracked him. He met with his former accomplice Mick Rory and told him that even though their previous partnership had not worked out well, things had changed and he needed a new kind of crew. He offered Mick the fire weapon he had taken from Nurblin and asked if Mick wanted to join with him, which he accepted.
Legion of Doom
Obtaining the Spear of Destiny
In 2014, Snart was found by the Legion of Doom and told him of his future with Rip Hunter and the Legends and how joining with them would result in his death. He agreed to join the Legion to get the Spear and avoid his fate. He appeared to Mick in 1916 who believed that he was just hallucinating him again. Snart tricks Mick into telling him the Legends' whole plan of acquiring the blood of Christ to destroy the spear, but Snart told him that he was a fool for destroying what was the greatest score of the universe. When the Legends found Sir Gawain and his map to the blood of Christ, Snart reveals himself to everyone and that this time he was real and had joined the Legion. He and Damien Darhk then had World War I German soldiers attack them. As the Legends were escaping, Snart told Rory that he was a fool for trying to save a bunch of losers that don't really trust or care about him. 
After the Legends got the blood, Snart and Darhk appeared and demanded the spear from them. Sara was about to go and reach for the spear but Rory took it away and joined Snart. Snart told the Legends that they would use it to make alot of fun changes to reality before he set off a grenade to get the two warring sides of the battlefield to fight to help in their escape. Eobard Thawne then sped him, Darhk and Rory away with the spear. Back at the Vanishing Point, Snart was praised for his skill and plan in getting the spear by both Thawne and Darhk. Rory thought that the spear would just be for the two of them but Snart told him that there was plenty of power to go around for everyone. Malcolm Merlyn then appeared with the Calebros Manuscript which would instruct them how to use the spear. He then joined the others in grabbing hold of the spear as Merlyn read the incantation to activate its power and begin to change reality to their whims. 
In the new altered reality, Snart altered it so as to have him and Rory be the rulers of the criminal underworld of Central City. They had an abundance of wealth which they used to own over half the city including some banks and even the Diamond Exchange. They were able to commit crimes and had full amnesty from the police. However, Rory was not feeling as though things were the same as before as with them now easily thieving with no danger, there was no real point to any of it. Thawne called them both to Star Labs, where he was now the owner, to talk to them of Malcolm Merlyn who he felt was getting to be a problem. However, before more could be said, Nate Heywood fought his way through security because he needed to meet with Thawne as he felt that something wasn't right with the current world. Snart, Rory and Thawne saw that Nate was starting to recall the past reality and Thawne asked for Snart and Rory to take him out and kill him. They brought him to the woods outside Central City but Rory stopped him before he could kill him. Rory argued that things weren't the same but Snart argued that they were better as now they ruled Central City and didn't have the Flash to bother them. However, Rory pointed out that they still had a speedster calling the shots. Snart assured Rory that he had a plan for dealing with Thawne and when Rory asked what it was, he told him not to worry about it. Rory argued that Snart claimed they were partners but only when he didn't have a plan of his own. Rory then knocked him out and escaped with Nate. 
He went back to Darhk and Merlyn and told him what had happened. Darhk was worried as Rory might decide to go to the other Legends and help them reform themselves. Merlyn angrily pointed out that they should've eliminated the Legends and had wiped Rory's brain of them. He then told Snart that he trusted Rory too much. Darhk summoned Sara and Amaya and told them to find Mick Rory and bring him back but also kill anyone that he was with. Snart then revealed that he placed a GPS tracker on Mick because he doesn't trust anyone. After the two ladies left, the three of them began to discuss Thawne. They formed an alliance against him as they were sure that Thawne would use the spear against them as he kept it and the secret of using it to himself. Snart was thinking of arranging a fake meeting to lure Thawne out into a trap but Darhk and Merlyn quickly shot his idea down. Amaya then returned and told them that Rory had found more of his friends and she and Sara were separated. A moment later, Sara returned and told them that they underestimated Rory and the others but wouldn't again. She tried to take Amaya and go off but Darhk was onto her and realized that Sara's memory had been restored. Snart and Merlyn watched as he ordered Amaya to kill Sara but then Sara restored Amaya's memory with a device and the two of them escaped. Snart moved to find Mick and saw that he was now alone. It seemed the other Legends didn't trust him anymore and Snart was able to learn that they planned to steal the spear before Thawne could destroy it with his new reactor device. The two of them informed Darhk and Merlyn and they planned for the Legends to distract Thawne and then they would swoop in and steal the spear for themselves. Rory and Snart were able to use their guns to incapacitate Thawne and everyone moved to try and get the spear. It ended up in Rory's hands and Snart asked for him to hand it over. The Legends reminded Rory what happened the last time he gave it to Snart but the Legion argued that it was Thawne calling the shots last time. However, Rory felt that Snart only thought him his dog and not his partner and then gave it to Amaya. Amaya started to use the spear but Snart shot her with the Cold Gun, freezing her into a block of ice. He then shattered her to pieces, killing her. He then took the spear, but Thawne recovered and stole it back before throwing it into the reactor, destroying it. Thawne then warned Darhk, Merlyn and Snart to not think of turning against him again or he would kill them. 
The Legion's Final Assault
To undo what the Legion had done, the Legends planned to go back in time to 1916 to stop the Legion from ever getting the spear at all. When Eobard learned of what they were doing, he went back in time to stop them. After killing Ray, Eobard then went and pulled Malcolm from his search of the Calebros to join him with the others in 1916. Snart, having just finished his meeting with Mick and reunited with Darhk, listened as Eobard explained that he was from the future where they had succeeded in using the spear but the Legends from that future had come to stop them and aid their past selves. Eobard told them to deal with them while he left to bring in backup. 
Malcolm, Darhk and Snart used their weapons to attack the Waverider before the Legends could leave with the spear. Their efforts, combined with an unexpected Time Storm, caused the Waverider to crash. They then started to approach as the Legends moved to engage them. 
Snart used his Cold Gun to shoot Ray out of the sky where he crash landed near him. Snart then saw future Mick holding Darhk down and Snart told him to let Darhk go but Mick said that he wasn't listening to him anymore. Snart asked if that was any way to treat his former partner, but Mick replies that he no longer had a partner, but a team. Snart remarked how Darhk told him that Mick went soft and he then shot a shard of ice that pierced Mick's chest, killing him. Ray cried out in anger at seeing Mick die and moved to avenge him. Before he and Snart could let out a shot at one another, a stream of fire hit Snart and knocked him out. Ray saw that it was the present Mick and was happy to see him alive. 
After Thawne's defeat, the Legends took the Legion and moved to deal with them. First, they took Malcolm Merlyn back to 2016 and left him back in his run down apartment to stew in his defeat and failure. Sara returned to the cell where they were keeping Darhk and Snart and they asked what they would with them as they were already dead in 2017. Sara then told them that they wouldn't be going to 2017. 
Mick Rory took Snart back to Central City in 2014, to the moment when he had been recruited to join the Legion. Snart initially thought Mick would kill him but he told his old partner that he was going to erase his memory and have him resume his place in history. Snart remarked that his place was to die in order to try and save the world but Mick said that he didn't die to save the world but to save his friends. Mick told Snart that his punishment was to go on and become a better man, and in turn make him a better man as well. Mick then erased his memories and left Snart to continue with his timeline from then on. 
Forcing The Flash to reveal himself
Even with sources like Iris West's blog reporting multiple sightings of the Flash, the speedster was still somewhat considered an urban legend. Knowing the Flash would make his more or less criminal activity harder to pull off, Snart started scheming for ways to make the citizens of Central City and the world aware of the Flash's existence. He first broke into a facility that held expensive foreign cars, with Mick initially under the false pretense that they were there to steal the vehicles. They left without stealing after it became clear that the Flash wasn't going to show up.
The duo's second attempt to lure the Flash was robbing the modern painting Fire & Ice, recently bought by Osgood and Rachel Rathaway at the cost of twenty-five million dollars. The CCPD showed up quickly, and with Cisco Ramon and Harrison Wells modifying their shields, they held off the effects of the Cold Gun; they, however, were not prepared for Mick's attack. During the attack, Snart tried to get Mick to focus, as he was being distracted by the flames of his own gun before it was hit. Because the Flash was still a no-show, Snart and Mick left the crime scene along with the art piece.
Fire and Ice
After their getaway, Mick managed to repair his heat gun (as Snart had insisted he get to know the weapon's inner workings after giving it to him). As they leveled their weapons at one another, Snart berated Mick for losing focus, however Mick retorted that Snart himself had not been as meticulous as he had in the past. Accepting this, Snart lowered his weapon and reminded Rory that with the Flash around, they could never run Central City, but offered him the chance to leave with the painting. However, he also pointed out that once they took out the Flash, the city would be theirs for the taking. Once Mick set the painting ablaze, he questioned how they would draw the Flash out, to which Snart noted that the Flash had partners too. To this end, the pair tracked down Caitlin Snow and kidnapped her.
After setting a trap with Caitlin as the bait, Snart then hijacked the television broadcast to reveal to the public that the Flash was indeed real, and issued a challenge to the scarlet speedster. As Caitlin was being rescued by Cisco and Joe West, the Flash confronted Captain Cold and Heatwave. Having planned to have Snart and Mick cross the streams of their respective weapons in order to neutralize them, the Flash ran as fast as he could to accomplish this, but to no avail. As he realized that he needed to instead go slower, Snart and Mick managed to knock him down. Thanks to the timely intervention of Eddie Thawne, the Flash managed to escape and put his new method to action, and finally succeeded in defeating the duo as Snart and Mick were knocked out.
While being processed at the Central City Police Department, Joe remarked at how Snart was finally being sent to jail. Later, as they were being transported to Iron Heights, Mick lamented at their failure, and questioned Snart on how his plan had gone astray. Snart stated that the public now knew of the Flash's existence, and so everything had changed. When the transport came under attack, Snart assured Mick that this was his plan, as his sister, Lisa, opened the transports doors to free them.
Running the town
Three months later, Leonard and Mick returned to Central City with Lisa. The pair was captured by mafia boss Vincent Santini but escaped and killed the boss' bodyguards. Snart told Santini that he was the one in charge before leaving. He later got his sister to lure Cisco to their base. Revealing that they had captured Cisco's brother, Dante Ramon, Snart forced Cisco to remake his and Rory's guns and make a third one for his sister. Later, he and Lisa attacked a casino and encountered the Flash, Leonard's primary objective. Snart convinced the Flash to back off by telling him that he had Cisco captive. Back at the hideout, Leonard made Cisco reveal the Flash's identity by threatening Dante's life. He re-encountered the Flash after an attempted heist and threatened to reveal his identity to Central City. Barry, however, convinced Snart to keep the identity a secret (and stop killing innocent people) while agreeing not to place Snart in the particle accelerator prison in S.T.A.R. Labs.
Moving the metas
After knowing that the meta-humans would die because of the particle accelerator that Eobard Thawne reactivated, Barry contacted Leonard to meet at Saints and Sinners and made a deal with him; If Leonard agreed to help him, Barry had to destroy every single piece of information in the world concerning him erased. Leonard also got his sister Lisa to help out with the job. When Team Flash and Leonard & Lisa got to Coast City airfield, Leonard double crossed the deal by getting Mark Mardon/Weather Wizard to destroy the plane that would transport them to Lian Yu, then getting all the meta-humans to try to destroy the Flash. When Jake Simmons/Deathbolt was about to kill the Flash, Leonard used his cold gun to kill Jake, claiming he owed him money. Leonard let Mark and Roy Bivolo/Rainbow Raider go and told the Flash that the meta-humans and he now owed him, by joining his "Rogues" and then road off with Lisa on their motorcycle.
During a robbery, Leonard was kidnapped by his father while his sister was injected with a specially designed thermite micro-bomb. When the Flash came to rescue him, Leonard told him he doesn't need saving. As the Flash asked him why his sister thinks he's been kidnapped, he was distracted by a cabinet closing in the back. Snart took the opportunity to shoot the Flash with his cold gun as his father intruded. The Flash managed to thaw out, but not before the two left the scene. Later, Leonard was approached by Barry, who offered help again. Barry said that Leonard may be a criminal with a code of honor, but his father doesn't seem to live under a code. He added that he would take Leonard down, and Leonard reminded Barry that he could reveal his secret. While planning for a heist, Leonard argued that Lewis's timing may be off. When David Rutenberg told Leonard to shut up, Lewis killed David brutally. Barry then came up with a plan to infiltrate the team by acting as their new tech guy, "Sam" and Leonard vouched for him. When they arrived at the crime scene, Leonard realized he was right about his father's timing being off. The two briefly argued while the Flash subdued the guards. After "Sam" cracked the security code, Lewis shot Barry, and Leonard showed remorse. Unbeknown to the two, Barry caught the bullet, but simply played dead. When they arrived at the vault, Leonard froze the lasers. Leonard told his father they only had 125 seconds before the alarms would go off. When the two left, the Flash confronted them. Lewis ordered Leonard to shoot him, but he hesitated. After the Flash said that Lisa was safe, Leonard immediately shot and killed his father. Leonard was then arrested taken into Iron Heights. Barry visited him and said that although he may be a criminal, he still has a light in him.
Get out jail free card
One month later, Snart was freed when Mark Mardon broke into jail, along with James Jesse, and proposed an alliance between the three to kill the Flash once and for all. However, Snart was uninterested in Mardon's plan and declined. Later, he went to the West house and warned Barry of Mardon and Jesse's plot, but told him that he wasn't going to work with them. Barry asked where they were but he declined to share any more information. When asked why he wasn't working with them and even why he was bothering to warn Barry, Snart just told him that there was no profit for him with their plan and he was paying back his debt to Barry. Before he could leave, Barry told him that he could see through Snart's act and that he was doing this because, whether Snart liked it or not, he had honor.
Joining Rip Hunter
Teaming up with heroes
In January of 2016, Snart and his partner Mick Rory conducted a heist on Central City Bullion Exchange and were making their escape in a mini-van when they were intercepted by Rip Hunter, who took them to Star City to be with the other heroes he had collected. Snart found himself waking up alongside Rory and they were joined by Martin Stein, Jefferson Jackson, Sara Lance, Carter Hall, Kendra Saunders, and Ray Palmer. Rip Hunter introduced himself to them all as a Time Master and told them that he gathered them all together in hopes that they would help him stop the immortal tyrant Vandal Savage. Snart and Rory immediately refused as they weren't heroes though Rip told them that in the time that he is from, they will all be known as Legends. He then showed them a vision of the world should Vandal Savage succeed and he then gave them coordinates and some time to make up their minds. While Rory is still against going with Rip as they were thieves and not heroes, Snart thought that the mission could provide them opportunities to steal and acquire treasures across time. Rory thought more about it and said that if Snart was in then he was in but he would be no one's hero which Snart agreed.
They went to the meeting place to find that the others had all also decided to accept Rip Hunter's offer as well. Rip then appeared and revealed his ship, the Waverider to them which they were all amazed to see. They traveled to St. Roch in the year 1975 where Rip Hunter wanted to find an expert on Savage by the name of Aldus Boardman. When they arrived he left Snart, Rory and Sara behind, as he felt that he wouldn't need their skills for the mission, though Jax also stayed behind as he was mad at Stein for drugging him and bringing him along without his permission. Sara became bored and wanted to go and get a drink which Snart immediately supported. Rory also wanted to go but Snart told Jax to stay behind. The three of them went to a bar and quickly found themselves in a bar brawl which the three of them enjoyed. They then returned to the ship to find the rest of the team attacked by a bounty hunter by the name of Chronos. In the ensuing battle, Aldus Boardman was fatally injured. Kendra angrily confronted Rip about Chronos' attack and he revealed that he had lied to them all when he said that they had become Legends. The reason he recruited them all was because in actuality they were all insignificant to the timeline. While Snart didn't care that he wasn't important to time, listening to Sara talk about changing their futures, along with stopping Savage, convinced him to stay with Rip Hunter. 
Due to Boardman's notes, they found that Savage was in Norway attending a black market arms auction. Snart decided to take point for this operation as he had experience with these type of gatherings. They found that Savage was there but not as a buyer but as the event's seller. He was selling a nuclear warhead and Snart's group quickly put in a bid when they noticed that some of the guards were looking at them in suspicion. However, they saw that no one else was putting in a bid after them which meant the warhead was now theirs. Snart tried to play it cool but when they were approached by Damien Darhk, asking who exactly they were, Stein arrogantly challenged him in front of everyone. Savage realized that they were infiltrators and ordered for them to be killed which made Snart give Rory the signal to light the place up with his Heat Gun. A fight then broke out with the Legends and Savage's forces and Snart and Rory fought back to back with their Cold and Heat Guns against any that tried to get at them. The sight of their guns, as well as the other Legends' powers and skills, made Savage realize that they weren't from around there. After they got away, Snart sarcastically pointed out that he had everything under control until Stein started to pick a fight with Darhk. Rip Hunter then revealed that the timeline had changed as Ray had left a piece of his suit behind which Savage's men found and will reverse engineer for their own purposes.
When Kendra found a dagger that could be used to kill Savage, Snart volunteered himself and Rory to steal it from the home of a wealthy Russian collector. Ray didn't trust them on their own so he went along with them. Snart and Rory cased the house and tried to make a plan to go in but Ray quickly went to disarm the alarm. However, Snart saw that Ray went after a dummy box which alerted the guards to them but he and Rory quickly took care of them. When they were inside the mansion, they quickly found the dagger along with other valuables. He and Rory wanted to steal them all though Ray told them they were only hear for the dagger and triggered the security system. While Rory went to find the fuse box, Snart went to try and manually disarm it. As Ray watched him work, he told Snart that he could've been an engineer instead of a thief though Snart wasn't interested. He argued that Ray wasted his own life to make himself a shrinking suit to try and play hero. They then were discovered by Savage, who turned out to be the owner of the house, and he had Rory and gunpoint. He then told them to call the rest of the team so that he could meet with Carter and Kendra. The rest of the Legends arrived and saved the three of them. While Carter and Kendra went after Savage, the rest of them engaged all of Savage's men. They took care of them but saw that Savage had killed Carter and had taken his body.
Trying to change his past
While the team was still in 1975, Snart and Mick convinced Jax to pilot the Waverider's drop-ship to Central City so that they could steal the Maximillian Emerald. After successfully obtaining the emerald, Snart directed Jax to his old address, at which point Mick realized Snart had only wanted to steal the emerald so that he could alter history so that his father would never be arrested. His father had tried to steal it back in 1975 but was caught and sent to prison.
While infiltrating his childhood home, Snart encountered his three-year-old self, who had come downstairs for a glass of water. Assuring him that he was a friend of their father's, Snart then advised his younger self to never let anyone hurt him. When Lewis appeared and sent the young Leonard upstairs, Snart presented him the Emerald, telling him to consider it a gift. Before departing, Snart cryptically told his father that he would prefer to just kill him but was sparing him because it would mean Lisa would never be born if he did. When he returned to Rory and Jax, he told how his father may not have been the best father but he never hurt him or his mother but that all changed when he went to prison. When he got out, he was a different man and took out his frustrations out on him, his mother and his sister and wanted to alter history so that his family wouldn't have such a hard past. When they got word that Rip and Sara had been captured by Vandal Savage, they went over to rescue them and take back Carter's body. Snart and the rest of the team moved to bury Carter and Aldus together where they vowed to find Savage and stop him.
Later on the Waverider, Snart requested Gideon to show him the new timeline, however, the A.I. told Snart that there was little deviation, as Lewis had instead been caught while trying to sell the Emerald to an undercover police officer and was sent to prison just like before. His father's and his family's past remained unchanged though Jax thought that it still meant a lot that he tried to do something like this for his family.
Choosing his side
He fights and helps his team on several occasions: against Valentina Vostok and Savage in the U.S.S.R, stopping Sara to kill Martin if the rescue mission fails, saving Mick and Ray from Koshmar. During the mission in Star City 2046, he understands that Mick becomes out of control and is forced to knock him before they return to the Waverider. Mick prevents him if he hits him again he will kill Snart.
When Time Pirates capture Eve Baxter and Waverider's crew, Mick betrays the team and join them, due to the Time Pirates's leader promising that he and Snart will be returned to Central City 2016. Snart is shocked by Mick's treason, he sides with Rip Hunter's team and defeats Time Pirates. Snart is volunteer to take care of Mick's fate, he takes him in an unknown place and presumably kill him, in reality he spared him, knocking him.
Later, Snart is captured by Chronos, the temporal bounty hunter of Time Masters who is revealed to be Mick. Snart said him that he always provided to search him but Mick responds that Time Masters found him, brought in the Vanishing Point and during more lives they trained him. Mick's goal is to kill his former comrades then killing Lisa Snart to do suffering his former partner. At the moment where Chronos is defeated, Snart arrives and stops the Legends to kill him revealing his true identity.
Helping Barry stealing alien technology for the speed force weapon
After being captured and rescued by the Legends and getting his hand regenerated by Gideon, he and the Legends journey to Siberia 1892 to locate Vandal Savage. While attempting to jump back on the Waverider, he felt he was being followed and he turn around with his Cold Gun and saw that it was Barry Allen. He was surprised to find the Flash in the past and Barry told him that he came to ask for his help because of his skills as a thief. He wanted to break into A.R.G.U.S. and steal a piece of alien technology. Leonard pointed out that the last time he came to him for help it didn't end well for him and asked Barry why he is trusting him now. When Barry took a while to answer, Snart told him to answer or he will jump on the Waverider and pretend the conversation didn't happen to which Barry answered that his fiancé Iris will die in one day if he doesn't help. He told him that they needed to break into A.R.G.U.S. to steal an alien power source for the Speed Force bazooka but his speed wouldn't help so he came to him for his expertise in thieving. Impressed with Barry wanting to be a thief he eventually agreed to help him under one condition: It would be done within his terms.He was taken back to S.T.A.R. Labs in 2017 where the rest of Team Flash was surprised to see him. Snart thought that it was because of their past though, unknown to him, it was because he was dead by that point in time. He told the team that the power source was likely at the lowest level of the facility, as it was the most secured area. Barry used an image filter to make him look like Lyla Michaels. The plan was that they would gain access by pretending to be taking Snart to lock up but weren't able to fully pass through the security checkpoint. Snart was impressed to see Barry violently attack the guards when their deception was discovered. He and Barry broke into the ARGUS prison and went into King Shark's cell retrieve the alien power source and eventually got caught by the real Lyla Michaels and her A.R.G.U.S. agents but let them walk free with the power source afterwards. Barry brought him back to Siberia 1892 and he told Barry that he might have a ruthless side to him just like Barry saw a hero in him into which they part ways as friends.
Refinding his partner and protecting the team
Sara suggests to Snart to settles scores with Mick. After the mission against Per Degaton, the child who will allow to Savage becoming the dictator in 2166, Mick and Snart fight. Mick wins but said to his partner he is already dead as the rest of the team because, he failed to kill them, then Time Masters sends the Hunters to finish the job.
In the Far West, Snart kills Billy Conlon, a member of Jeb Stillwater's Gang, to save Martin. After Jeb Stillwater's death by Rip, Snart joins the fight against the Hunters, and they are all killed. But Mick learns of one of Hunters that Time Masters launched the Omega Protocol : The Pilgrim. She chases the young versions of the team but she is finally killed by Snart, Rip Hunter's team and the young Rip Hunter.
In 2166, Snart fights with the Team against Savage and his giant robot the Leviathan. He meets Savage's daughter, Cassandra and convince him that his father is the real villain with Gideon's help, then she joins them. During the fight, Ray destroys the Leviathan, Savage is defeated but not killed because Kendra discovers that he hypnotised Scythian Torvil (the reincarnation of Carter Hall), then she spares him for the moment to cure Carter. Before of leaving, Snart convinces the leader of the Rebellion to accept Cassandra to defeat Savage's army.
Getting close to Sara Lance and hiding from Time Masters
After the Leviathan's destruction and Savage's capture, Snart suggest to kill him but Rip prefers to bring back to Time Masters because he disrupts the Timeline many times. During the journey, Snart gets close with Sara since the beginning of the adventure. When he understands that there is a problem, he hides with Sara but Ray, Kendra, Martin and Mick are captured by Time Masters who are revealed to be Savage's accomplices from the beginning.
Destroying the Oculus
Once Snart and Sara freed the rest of the team from their holding cells in the Vanishing Point, Rip decides to go back so they can destroy the Oculus to make sure their actions won't be controlled meaning they would have a chance to stop Savage. Before the fight, Snart wonders if there is a future for him, for Sara and for us. Sara understands that Snart tries to steal her a kiss and said him that he makes progress. Palmer set it to self-destruct but found out it had a fail-safe meaning someone had to stay behind to make sure it blew up. Rory decided to stay behind and the rest of the team left towards the Waverider but Snart went towards Rory to knock him out so he could stay behind, sacrificing himself, Sara gives him a kiss of goodbye. The team's mission was successful, as the incoming explosion destroyed the Oculus device, along with many of the structures around it in the Vanishing Point killing Zaman Druce and Snart.
In a possible future, Leonard can be seen fighting alongside the Flash, Ray Palmer/The Atom, and Sara Lance against an unknown metallic adversary. Barry caught a glimpse of this when traveling through the Speed Force.
Leonard was fondly remembered by the rest of the Legends for his sacrifice, especially Mick Rory, who, during his goodbye visit to a 2013 version of Leonard, thanked him for always being a hero for his sake, despite the younger Leonard not quite knowing what he meant. Barry Allen also appeared worried for Leonard, and was quite upset when the Legends told him of Leonard's demise, but remarked that he became a hero as Barry believed he could be. As Mick Rory continued drinking, while thinking about his new role on the Legends, Leonard appeared as a hallucination to Mick, trying to convince him to abandon the team and go back to the life of crime.
Leonard's Cold Gun was given by Mick to Ray Palmer, for his temporary role as "Colonel Cold" while his A.T.O.M. Exosuit was destroyed. Additionally, his images and voice were used by Barry Allen to create holograms that allowed to trap Leonard's old adversary Mirror Master.
Leonard appears as the Speed Force to Barry while trying to save Wally and criticizes him about influencing him to be the hero. He also mentions to Barry about sacrificing himself for the Legends to which he showed a dislike about it. When Barry asks where's Wally, he attacked Barry by pinning him to the ground in ice until Jay Garrick appears and defends Barry from his cold blast.
Leonard is a ruthless man who has a calm, composed and level-headed demeanor, rarely ever losing his temper or giving into emotions. Although he never finished high school, he is intelligent and patient, staking out a job for months before making his move, emphasizing timing, precision, and minimizing possible leads on him and his activities by refusing to kill unless necessary. He was clever enough to unlock the Montgomery 3000, a 25-ton door that can withstand a 30-megaton nuclear blast, by himself, without any of the three passcodes needed to open it. He was also clever enough to deduce that what stopped his job at the armored car was in fact a man, and that he would need a weapon to halt Barry, choosing the Cold Gun for this very reason. Leonard has, however, begun to revel in his new-found weapon's power, and his battles with the Flash have begun to alter his perceptions of how the job works, transforming from an armed robber into a "supervillain" that would directly challenge the Flash. The change in his demeanor is astounding, as Leonard can be seen acting much more ruthless before meeting the Flash: he killed the man who supplied him the Cold Gun for the sake of convenience, and before that tried to kill Sam Scudder and Rosa Dillon for going against his orders as a crime boss.
Despite his unapologetic criminal lifestyle, Leonard sees and declares himself as a man of his word. This is demonstrated further, when he promises to release Cisco if he tells him who the Flash is. Although he does torture Dante to get this information from him, he keeps his word afterwards and lets both Cisco and his brother go. However he doesn't always keep his word when he betrays his alliance with Barry by setting the meta humans free. Leonard simply defends his actions by claiming that he is a criminal that saw an opportunity and used it for his own benefit because that's who he is.
Regardless of Leonard's ruthless nature, one of the only things he does care about is his younger sister Lisa, who he has a close relationship with her, despite her immaturity. He severely despises his father Lewis, for what he did to him and his sister; for physically abusing them as children for no apparent reason, he became disgusted when Lewis planted a bomb inside Lisa's head in order to manipulate him into helping him with one of his heists, however, after Barry told him that the bomb was removed from Lisa, without hesitation he killed his father for what he did to his sister. He is also quite prideful; Barry deduced that Snart was going along with his father's plans because Lisa was being threatened because he concluded that Snart would have tried to dig the miniature bomb out of his own head if one was planted in him. A similar case happened in "Left Behind", as while Snart was handcuffed to a wall, he managed to reach his Cold Gun, and when he could not use it while he was restrained, he used his feet to fire the gun and intentionally turn his hand to ice and then proceeded to shatter it against the ground, despite the great pain of it. He still walked out without much grief over his injuries, focusing on escaping and the task of stopping the team from killing Chronos, who was actually Mick Rory.
Despite being enemies most of the time, Leonard and Barry seem to possess a mutual respect for each other; although he betrayed him, Leonard saved Barry from certain death at the hands of Jake Simmons. A few months afterwards, his liking of Barry increased to the point he felt genuine remorse after his father shot him. Barry also visited Leonard upon the latter's arrest. Leonard even refused to go along with Mark Mardon and James Jesse's plan to kill Barry and instead warned him of what they were up to before departing. Leonard deeply cares about his sister, going as far as working with a man he slightly hates (due to his more moral and honorable ways) in order to keep her safe. All of these qualities have led Barry to believe Leonard has good inside of him and that he'll eventually change his ways (although Leonard jokingly remarks that heroes don't get paid enough). Another instance is when Snart is broken out of prison, instead of going after Barry to kill him, he warns him. When Barry asks where the other two (Mark and Jesse) are, Snart says "Barry and his friends love to solve a good mystery" and goes to leave. Barry snorts at this and tells Snart that he's there because he (Barry and co) saved Lisa and Snart doesn't like owing him one and that's called honor. Snart is quiet for a brief moment before wishing Barry and Iris merry Christmas and leaves.
Leonard also possesses a code of honor when it comes to his teammates, shown when he becomes a full-fledged member of Rip Hunter's team after Carter Hall is murdered by Vandal Savage. When he deduces that Hunter wants Sara Lance to kill Martin Stein in order to prevent the devastation of the Cold War in the present time if Stein breaks and agrees to help the Soviets create their own Firestorm, Leonard is against the idea as he doesn't believe in turning on his own team members and manages to talk Sara out of shooting Stein, showing a profound understanding of her nature and drives and expertly employing reverse psychology. Proving himself not a hypocrite, Leonard also refused to kill Jax when he was mutated by Savage into a feral bird-creature, allowing his team to ultimately cure Jax. When he threatened Sara Lance at gunpoint, trying to force her to escape the Vanishing Point on the timeship while abandoning the rest of the team, she stood her ground without fear, knowing that for all his threats, Snart was no longer the cold-blood murderer, but a hero, who'd never kill his teammates. That proved to be true after Snart admitted his bluff and helped Sara with the rescue of their team members captured by the Time Masters. During the rescue they encountered Mick Rory, seemingly brainwashed into being Chronos once again. Snart refused to attack his friend, which was recognized by Rory, who turned on the Time Masers instead.
Leonard is incredibly charismatic, maintaining the image of a "lovable rogue", using his charms to get important information, obfuscate his thievery or convince people of his trustworthiness. This way, he gained the trust of Valentina Vostok and Cassandra Savage. Leonard himself was interested in Sara Lance, flirting with her on occasion, drinking and playing cards with her and even apologizing for being "a jerk". However, Sara declined his advances with a smile on her face, saying that he'd need to be a master thief to steal a kiss from her. Despite this, Sara and Leonard kissed at the Vanishing Point, when Leonard decided to sacrifice his life to destroy the Oculus device in Mick Rory's and Ray Palmer's stead.
Being prone to controlling or playing others, Leonard absolutely detests the idea of being controlled or manipulated by anyone or anything. He values his free will and the ability to make his own choices and will do anything to hold on to that freedom. This is a trait that is so dominating in his personality that he destroyed the Oculus in the Vanishing Point not just out of compassion for his teammates, but because he wanted to make sure that no one else would be manipulated by the "Time Bastards" as he referred to them.
- Expert engineer: While not as proficient as Cisco Ramon or Ray Palmer, Leonard was very skilled in electrical engineering due to his father forcing him to come with him on heists when he was a child. Once Leonard obtained his Cold Gun, he had taken the gun apart and put it back together so many times that memorized how to repair it by hand. Leonard was also capable of updating and adding additional features to his Cold Gun.
- Expert escape artist: In addition to be able to avoid capture by the authorities, Leonard was also skilled at escaping them after being captured; with Mick Rory noted that they have escaped a few prisons together. Leonard had also demostrated the ability to effortlessly slip out of handcuffs.
- Expert hand-to-hand combatant/Brawler: Despite his composed demeanor, Leonard was a capable unarmed fighter. When taken captive by the mafia, Leonard and Mick quickly broke free from their confinements and killed most of the mobsters with their bare hands. However, between him and Mick, Leonard proved to be the inferior combatant as Mick quickly gained the upperhand and delivered a severe beating to Leonard.
- Expert marksman/Firearms: While normally preferring to avoid killing when not necessary as not to not sully his plans, Leonard was highly proficient with firearms. Leonard had demonstrated great proficiency with his Cold Gun allowed him effectively hit the Flash while he was running at superhuman speeds and using it for various creative solutions. While in the Old West, Leonard demonstrated to outdraw a gunman with a revolver and a skilled sharpshooter as seen when he used a rifle killed a man with head from a window several buildings away.
- High-level intellect: Leonard's most noticeable and dangerous trait was his high intelligence, making him a threat to a meta-human such as the Flash. Despite never graduating from high school, Leonard had repeatedly shown considerable knowledge in subjects such as biology and engineering. Leonard was also able be very persuasive and charming able to seduce Valentina Vostok and able to sway the loyal Cassandra Savage, to turn on her father, Vandal Savage. Leonard also had exceptional instincts that he considered to be almost like a "sixth sense", he was able to tell when something bad was about to happen just through a bad feeling.
- Indomitable Willpower/High tolerance for pain: While selfish and ruthless by nature, Leonard was capable of great conviction. As when handcuffed to a wall by Chronos, Leonard with almost no hesitation used his Cold Gun on his hand and shattered it to escape; he then immediately sought out the Legends to warn them.
- Master tactician: Leonard was a master planner and schemer, as he repeatedly developed plans that he pulled off with usual success. Leonard's tactics are based on timing, precision, and preparation as he would often spend his time studying every detail of his heist from studying the security detail to police response times. In his nature for preparation, Leonard has repeatedly displayed an unusually adept memory being capable of memorizing the details of every job through tactical anaylsis; Mick has mentioned that Leonard usually counting the seconds on the clock waiting for his plan to go off without any problems.
- Master thief: A career criminal, Leonard was regarded as a master thief who spent months preparing for a job and never giving up until he completed it; in his life Leonard pulled off armored car heists, jewelry theft, and bank robbery with the utmost skill. Leonard was also skilled in the art of pick pocketing able to effortlessly swap specific items for his mission while stealing their wallets at the same time.
- Cold Gun: Generating a beam of absolute zero temperature, the weapon freezes whatever it touches and creating solid ice. It can also slow down the motion of fast moving molecules, specifically those of the Flash, retarding his accelerated healing and vastly reducing his speed. It also gives off bright white and blue flashes that the user protects their eyes from with goggles.
- Goggles: Leonard also wears a pair of blue wraparound goggles, which are designed to protect his eyes from the flashes given off by his cold gun.
- "Legends of Yesterday" (mentioned)
DC's Legends of Tomorrow
The Flash: Season Zero
- Although he's called Captain Cold by Cisco, he refers to himself as simply "Cold".
- He is the first non-metahuman villain Barry has faced, in addition to being the first Flash villain to escape custody.
- Leonard Snart has apparently watched Star Wars, as shown in Pilot, Part 1 of Legends of Tomorrow when he refers to Chronos as "Boba Fett".
- In the episode "Fail-Safe" Leonard Snart says: "This isn't my first prison break" referring to his criminal past, but also to the series "Prison Break" where he plays the role of Michael Scofield, trying to break out his brother Lincoln Burrows, played by Dominic Purcell, who is Mick Rory/Heat Wave in Legends of Tomorrow.
- Snart's alter ego, Captain Cold, has action figures designed after him. William Clayton was seen playing with one with his father, Oliver Queen.
Behind the scenes
- In the DC comics, Leonard Snart, alias Captain Cold, is an enemy of the Flash, an "honorable thief", and the leader of Rogues, an often-changing team of criminals operating in Central City and Keystone City, united to oppose the Flash whenever he tried to stop their heists. His weapon of choice is a cold gun, able to fire a ray that slows things down on a molecular level, leading to intensive blasts of ice and cold that can stop anyone in their tracks (leading to Snart calling himself the "Master of Absolute Zero").
- In the comics, Leonard is called "Len", a shortening for his full name.
- Wentworth Miller, the actor behind Captain Cold pitched Leonard as pansexual to the writers, stating that if Captain Cold met another superhero or villain with the right combination of smarts, and wit, and badassery, he'd be into them. Their sex or gender would be totally irrelevant.
- Leonard wears a blue parka along with the Cold Gun's complementary goggles when taking on the Flash and derailing the train and when recruiting Mick, a reference to his costume in the DC comics. He continues to wear the outfit when in action after first seen in that getup.
- Most of the Flash episodes in which Leonard Snart appears contain the word "Rogue". i.e. Going Rogue, Revenge of the Rogues, Rogue Time, Rogue Air, Family of Rogues and The New Rogues. In the DC Comics, Leonard is the founder and leader of the Rogues, a team of super criminals, united to be able to oppose the Flash.