Katey Hagen was once a noted actress/ model who became the villain Clayface after over exposure to the chemical Renuyu. She is portrayed by Billie Piper.
Katey Hagan/ Clayface was a professional actress and model. Soon she became disfigured by a thug who threw acid at her face. Because of this finding work for her became more of a challenge and feared the worst of her Career until the CEO of Sionis Industries, Roman Sionis offers her a second chance by giving her an untested chemical called Renuyu, which has the ability to reconfigure a persons face. She did not know the true nature of the drug. In return Sionis ordered Katey Hagen to commit various crimes for him. When Katey Hagen outlived Sionis's usefulness, he revealed that it was him that hired the thug to disfigure her face and then Sionis ordered the thugs to kill her by hypersaturating the actress/model with the formula by drowning her with a canister of Renuyu.
Instead of killing her, the cream bonded to her cellular structure transforming her to a hulking humanoid mass of the cream. The transformation gave Katey Hagen the ability to transform into any shape or form that she desired.
In desire for revenge against Roman Sionis, she disguises herself as the thug who disfigured her and when she came to Roman Sionis, she trapped Roman Sionis on the wall using her powers, covered his face with kerosene and then sets his face on fire which left Sionis's face severely burnt, Batman then fought and tried to reason with Clayface and in the end, she as electrocuted and faked her death escaping leaving only a shell.