Clayface

After being nominated for an Academy Award, actor Matt Hagen attends a party with his childhood friend and fellow actor Corey Bowery. There, he meets actress Mia Torrez and spends the night with her despite Corey's warning that she is the girlfriend of crime lord Markos Szabo. The next morning, Szabo and his men ambush Matt and disfigure his face with a knife. Although Matt reports the attack to the police, Szabo avoids prosecution due to a lack of evidence and control over the corrupt Gotham police. Mia later falsely claims in a television interview that Matt had drugged her. Unable to find work due to his appearance and Mia's allegations, Matt runs out of money and returns to his childhood home in the Gotham City slums.
After multiple botched surgeries, Matt learns of Caitlyn Corr, a doctor who is developing a nanite treatment capable of rapidly healing damaged tissue and skin. Caitlyn initially hesitates to use Matt as a test subject, but her fiancée, detective John Borrelli, who is investigating Szabo, encourages her to help him. The treatment initially succeeds, allowing Matt to return to public life with his face apparently restored. When his face begins melting during a red carpet event, however, Matt panics and returns to Caitlyn. Against her wishes, he injects himself with a larger dose of nanites, seemingly curing the problem.
Matt subsequently discovers that he can instantly recover from any injury. Although thrilled by his abilities, Caitlyn grows concerned. While flying home after visiting Corey, Matt learns from a news broadcast that his former manager, Frank Fitzpatrick, now works for Mia and Szabo. Matt briefly loses control of his powers but, with Caitlyn's guidance, discovers that he can alter his facial features and voice to impersonate anyone. He confronts Frank, who admits to betraying him to conceal his embezzlement of Matt's earnings, and reveals that Corey helped him ruin Matt's reputation. Unable to fully control his powers, Matt accidentally kills Frank and assumes his appearance to escape, then tracks down and willingly murders a remorseful Corey by suffocating him inside his body.
John begins to suspect Szabo of the killings, prompting Szabo to threaten both John and Caitlyn. When Caitlyn visits Matt, he confesses he loves her, but she hesitates to reciprocate due to her relationship with John. After one of Szabo's men follows Caitlyn, Matt kills him and infiltrates Szabo's club, massacring the gang before confronting Szabo and Mia. Matt forces part of his body into Mia's throat, suffocating her. He then cuts his own face in a manner identical to how Szabo's men had disfigured it and lets his blood drip onto Szabo's face. As Matt's wounds regenerate, the nanites in his blood crush and dissolve Szabo's face, killing him.
With Szabo's criminal empire destroyed, John visits Matt to verify his whereabouts. Caitlyn realizes that Matt is responsible for the murders and returns home to tell John everything. After the conversation, she discovers the real John's corpse and realizes that she has been speaking to Matt in disguise. Convinced that their romantic feelings are mutual, Matt declares that they can finally be together and attempts to kiss her. Horrified, Caitlyn attacks him with a taser and activates the nanites' "kill switch", causing his body to melt away into the sewers, while Caitlyn informs the police. Unable to find any trace of him, the authorities dismiss her account. Matt is declared missing, and Caitlyn abandons her research.
Later, Caitlyn gives a dollar to a homeless man, unaware that he is Matt, who survived and is living in Gotham's sewers. Using his clay-like flesh, Matt creates a replica of Caitlyn and acts out a scenario in which they reconcile and kiss. As he transforms into a hulking form, Matt roars in rage.