Jayna was an alien from the planet Exor. She and her brother Zan were Exorian metas whose parents died during a plague. No one adopted them because they were freaks, but they were eventually taken in by a kind circus clown while being forced to perform for the circus. They escaped and eventually made their way to Earth, joining the Justice League. Jayna had the ability to transform into any animal whose name she could verbally remember, even if they were mythical. However, saying the name of a wrong animal would cause her to turn into that animal. She also gained the powers of the animals she transformed into, once defeating Superman as a Kryptonian animal due to the fact that Kryptonian life was enhanced by yellow suns. Touching her brother could break her from mind control.