Byth Rok and Erik Razar were motivated by their criminal tendencies which led to them gaining tremendous powers both diverse and deadly. As shape changers, they were formidable foes indeed.
Erik was from the same planet as that world's Hawkman and his ally the Flash, known as Earth-Two. When he was sentenced to be executed, the electricity had a metagenic effect on him allowing him to transform into any animal he desired to become. After a clash with the Scarlet Speedster, this defeat climaxed in his death. Prior to this, a scientist named Princess Helene had experimented with shape changing technology, only her battle with the Flash also led to her transformation into a black widow that quickly died. Helene's counterpart on Earth-One was the foe of Firestorm known as Silver Deer, herself a shape changer.