Very little is known about Cottonmouth other than before he joined the Serpent Society, he was a common criminal in Mobile, Alabama. He was presumably enhanced by Roxxon Oil in order to gain superhuman abilities. He was then contacted by Sidewinder to join the criminal organization.

During the mission to murder MODOK, Cottonmouth and his comrade Death Adder brutally attacked their target, and before Captain America was able to save him, the pair succeeded in killing him. Cottonmouth later attempted to kill Captain America alongside Rattler, Diamondback, and Death Adder, though he was eventually defeated and imprisoned. However, Sidewinder quickly freed Cottonmouth which allowed him to continue on with the Serpent Society.

More recently, Cottonmouth has been seen battling Luke Cage and Black Panther. He also briefly allied himself with Hawkeye, Plantman, and Headlok to escape from prison.