Below is a list of characters who originally appeared in the DC comics multiverse prior to the episode's airing, by appearance.
Characters first appearing in Arrow:
Comic book tie-in characters
Novel tie-in characters
- Thea is based on the comic book character, Mia Dearden, the second person to take on the mantle of Green Arrow's sidekick, Speedy, and the first to be a female. Though the name "Thea Queen" originates from the show.
- Even though Laurel is the direct adaptation of Black Canary in Arrow, her younger sister, Sara Lance, who is an original character specifically created for the show and was previously known as "The Canary", is also based in part on the same character. Sara is also an adaptation of another comic book character, the White Canary.
- Felicity's code name had been used in the comics only once, but by another character. It was introduced as "Overwatch-One", the code name of Terry Sloan in Earth 2: Society series.
- Even though Malcolm is the direct adaptation of Merlyn in Arrow, Tommy Merlyn, who is in part an original character specifically created for the show, is also based on the same character. Both Malcolm and Tommy were later canonized in the comics as parts of the Dark Archer/Merlyn legacy.
- Due to the several iterations of the Royal Flush Gang, both versions of King and Ace are considered to be adaptations of the many iterations of each of the characters from the comics, respectively.
- Both characters are based on the original Black Canary from the comics, Dinah Drake-Lance. However on the show, the character is split into two unrelated and altogether separate individuals.
- In the comics, Isabel is also known as "The Queen". Ravager, which is the alias she is informally given on the show, is the alter ego of several comic book characters, most of them related to Slade Wilson.
- Sebastian's parents are both based on comic book characters as well. Sebastian Sangre is based in part on Sebastian Blood VIII who is the father of Sebastian Blood IX, with "sangre" being the Spanish word for blood. Maya Resik is based in part on Mother Mayhem. Both women who adopted the title, Anna Resik and May Bennett, were mothers of different Sebastian Bloods.
- Sin's real first name on the show has been revealed to be Cindy with her last name being still unknown. In the comics, her name is Cynthia and she got the surname "Lance" after she got adopted by Black Canary.
- Richard is based on The Seattle Slasher, an otherwise unnamed serial killer from the mini-series Green Arrow: The Longbow Hunters.
- Steelgrave is seemingly based on the comic book character, Professor Steelgraves.
- Even though Werner Zytle is the direct adaptation of Cecil Adams in Arrow, the drug dealer, known as "The Count" or "Cecil Adams", who is in part an original character specifically created for the show, is also based on the same character.
- Even though his first name was changed to "Curtis" for the show, he is based on the comic book superhero Michael Holt, the second Mr. Terrific.
- Paul is a reimagining of Michael Holt's spouse, who in the comics is a female and is named Paula Holt.
- Evelyn Sharp is an amalgamation of two characters; Evelyn Crawford/Starling and the vigilante, Artemis.
- In the comics, Adrian Chase is known as the crime-fighter Vigilante. However, on the show, Vigilante appears as a totally different character, while the name "Adrian Chase" is used only as an alias by Prometheus.
- Even though the character originates from the mainstream DC comics, his last name was never revealed, as he was only known by his first name. Unlike the comics, in Arrow: Season 2.5 he is given a last name as well, Nassar.
- Even though in the comics his first name is unknown, he is based on a character known as Master Jansen who first appeared in Flash #218.
Characters first appearing in The Flash:
Comic book tie-in characters
- Cameron Scott ("Plastique")
- Grant Emerson ("Power Outage")
- Will Everett ("Power Outage")
- Bea da Costa ("Power Outage")
- Mal Duncan ("The Nuclear Man")
- Evan McCulloch/Mirror Master ("The New Rogues")
- Julie Greer ("Invasion!")
- Cheetah ("Infantino Street")
In-universe fictional characters
- Rita Farr ("Things You Can't Outrun")
- Blue Devil ("Things You Can't Outrun")
- Nighthawk ("Power Outage") *
- Cinnamon ("Power Outage") *
- Joker ("Chronicles of Cisco")
- Rebecca Sharpe/Hazard ("Luck Be A Lady")
- Amunet Black/Blacksmith ("Girls Night Out")
- The Mechanic (unknown episode)
- Breacher (unknown episode)
- Ralph Dibny/Elongated Man (unknown episode)
- Even though Eobard is the actual version of Reverse-Flash in The Flash, Eddie Thawne, who is in part an original character specifically created for the show, is considered to be partly based on the same character, due to the similarity of their names.
- Even though the character originates from the comics, his last name was never revealed, as he was only known by his first name or his alias. Unlike the comics, on the show he is given a last name as well, Gibran.
- In the comics, Baez's first name is actually Lashawn but it was changed to Shawna for the show.
- Brie is a reimagining of the villain known as the Bug-Eyed Bandit, who in the comics is a male and is named Bertram Larvan.
- In the mainstream DC comics, King Shark's real name is Nanaue.
- In the mainstream DC comics, there are two different versions of Doctor Light, with the second one being a female of Asian heritage. Though it is not Linda Park but Kimiyo Hoshi.
- In the mainstream DC comics, Hath-Set and Vandal Savage are two separate characters, with only the former being involved in Hawkman and Hawkgirl's origin, but in this version they are combined.
- Even though the character originates from the comics, his real name was never revealed, as he was only known by his aliases, "The Turtle" or "Turtle Man". Unlike the comics, on the show he is given an actual name as well, Russell Glosson.
- In the comics, "Reverb" and "Rupture" are the aliases of Armando Ramone, the brother of Paco Ramone a.k.a. Vibe (a former version of Francisco "Cisco" Paco Ramon).
- For a large part of the second season, Hunter Zolomon masqueraded as "Jay Garrick" before the actual character's introduction on the show.
- In the comics, Albert Desmond is a man with a personality disorder, acting under two separate supervillain identities; Mr. Element and Dr. Alchemy. A number of people succeeded Albert in both these identities. This is adapted on the show as "Alchemy" is just an avatar of Savitar that he uses to possess people of different universes, with Julian being among them.
- Rosa is a reimagining of the villain known as the Top, who in the comics is a male and is named Roscoe Dillon.
- In the comics, the aliases of Nighthawk and Cinnamon were used by legendary bounty hunters, Hannibal Hawkes and Katherine Manser (reincarnations of Khufu and Chay-Ara), during the 19th Century. On the show, Hawkes and his unnamed partner do exist but did not use these names. The two aliases are used as fictional film characters on the present day instead.
- In the comics Hunk Norvock was a crime boss an an enemy of Jay Garrick's The Flash, affiliated with Clifford DeVoe. In the series however no first name was given as of yet and th surname is spelled differently.
Characters first appearing in Constantine:
- First of the Fallen ("Non Est Asylum")
- Cedella ("The Devil's Vinyl")
- Judith ("The Saint of Last Resorts") *
- The character is loosely based on Baron Winters, a mysterious occultist affiliated with John Constantine.
- Nommo is an adaptation of the comic book character Doctor Mist.
- In the comics Judith is a minor character and a member of the Newcastle Crew. She has made only a few small appearances and most of the time she is just mentioned by other characters. Her last name is unknown.
Characters first appearing in Vixen:
- Even though Mari is the actual version of Vixen, her ancestor, Amaya Jiwe, who is an original character specifically created for the show, is also based in part on the same character.
Characters first appearing in Supergirl:
Comic book tie-in characters
- Lois Lane ("Stronger Together")
- Perry White ("Stronger Together")
- Rao ("Truth, Justice and the American Way")
- H'ronmeer ("The Martian Chronicles")
- Reign (unknown episode)
- M'yrnn J'onzz (unknown episode)
- Gail Marsh/Psi (unknown episode)
- Guardian is the name of several characters in the DC canon. However, while multiple people have donned the mantle of Guardian, Olsen is not one of them.
- Even though Winslow is the actual version of Toyman in Supergirl, Winslow "Winn" Schott Jr., who is an original character specifically created for the show, is also based in part on the same character.
- Amelia is a gender-swapped version of comic book character and supporting character in Superman comics, Emil Hamilton.
- In the comics, the name "Mon-El" is only an alias for the character, as his real name is Lar Gand. On the show, the character is split in two; Mon-El and his father, Lar Gand, the prince and king of Daxam, respectively.
DC's Legends of Tomorrow
Characters first appearing in DC's Legends of Tomorrow:
- Kanjar Ro ("Marooned")
- Tzin-Tzin ("Left Behind")
- Onyx Adams ("Left Behind")
- Tigris ("Left Behind")
- Malaq ("Left Behind")
- Fadir Nasser ("Left Behind")
- Hannibal Hawkes ("The Magnificent Eight") *
- In the comics, Chronos was a supervillain obsessed with time, and an enemy of Ray Palmer, the Atom. However, while multiple people donned the mantle of Chronos, Mick Rory was not one of them.
- In the comics, Grant is known as either Ravager or Legacy, but in the show he takes on the moniker of Deathstroke, like his father, Slade.
- In DC Comics, Bonnie Baxter is a member of the Time Masters and an ally of Rip Hunter, much like the similarly-named character on the show.
- In the comics, Sgt. Rock's real name is Frank Rock, though on the show it hasn't been mentioned yet.
- In the mainstream DC comics, Albrecht Krieger a.k.a. Captain Nazi and Ubermensch are two separate characters but in this version they are combined.
Freedom Fighters: The Ray
Characters first appearing in Freedom Fighters: The Ray:
- Raymond "Ray" Terrill/The Ray (unknown episode)
- Uncle Sam (unknown episode)
- Phantom Lady (unknown episode)
- Black Condor (unknown episode)