Viper sent Boomslang and Cobra under Copperhead's lead to poison the water supply of Washington DC. Copperhead had no respect for Cobra's experience and frequently belittled him, reminding him that he was in command. While escaping through the street, the three villains found the citizens turned into snake-men similar to their teammate Slither, from which they deduced the "poison" actually was a mutagenic agent. When they reached their escape ship, they were intercepted by the Captain and Diamondback. The Captain blocked Copperhead's blasts with his shield and knocked him out with one punch.
Copperhead remained with the Serpent Society after Viper left.