Fan Casting Copperhead in Batman: Arkham Origins

At some point during her contracted status, Copperhead had managed to deduce that her "employer" had actually been impersonated by the Joker. While he searched for Black Mask at the Steel Mill, Batman encounters one of Joker's Henchmen dying inside the elevator shaft. Batman discovered that he was killed by poisons inside his body. While Batman interrogated Black Mask, Copperhead poisoned him with her claws, said he was already dying slowly and left. Batman scanned the poison and had Alfred synthesize a cure.