K'hym was a Green Martian living with her father, mother and sister on Mars. However family was attacked by the White Martians a subterranean race who then wiped out dozens of their people in a Martian holocaust. K'hym was killed alongside her mother and sister leaving only J'onn alive.
- "Strange Visitor From Another Planet" (flashback)
- "Survivors" (mentioned)
- "The Darkest Place" (hallucination)
- "We Can Be Heroes" (indirectly mentioned)
Behind the scenes
- In the comics, K'hym J'onzz is the only daughter of J'onn J'onzz, who was killed along with her mother in the plague that destroyed most of the Martian population.