Karla was created by Nick Cardy and Bob Haney, and her first appearance is in Aquaman #24.
Major Story Arcs
Karla is an Aquaman foe whose hair has been turned to living flame. She controls her "hair" psionically for a variety of combat uses. Her fire is not affected by the undersea environment. Her body is invulnerable to the fire. She was the Leader of the Terrible Trio. Karla is not able to breathe underwater, she uses scuba-diving equipment.
Karla has revealed little of her past. She has mentioned being mutated in an industrial accident. She soon found herself rejected by men and vowen to get revenge on them. Her career in villainy had begun. She apparently hired herself out as a mercenary. Mysterious employers known as "Them" (actually aliens) hired Karla, Fisherman and the Un-Thing to perform a peculiar mission: dispose of the planet's oceans.
Karla and her allies at first used satellite technology to perform their mission. But Aquaman, Aqualad and Mera negated the effects. The time for a personal confrontation had come. Karla trapped Arthur and Garth in a cage created by the living flame of her hair. Meanwhile Un-Thing successfully captured Mera. The Trio knocked out the male heroes but left them behind, only abducting Mera. The two knocked out foes recovered in time and went for a rematch. This time Mera used her hard-water powers to capture Karla, while the two male villains failed poorly.
Then the aliens revealed themselves and attempted to eliminate all six combatants. Aquaman acted quickly to save them from death. Karla was impressed enough with him and angered enough with the aliens to team up with the King of Atlantis. She saw to it that her double-crossing employers died in an explosion. Aquaman turned over the trio to the authorities but suggested lenient treatment for Karla.