King Cobra also known as simply Cobra or his real name Klaus Voorhees, is a supervillain enemy of Captain America and the Avengers, and the leader of the Serpent Society. Klaus Voorhees was an ex-convict who became a scientist's assistant, and helped to work on a universal snake venom anti-toxin. When Klaus became jealous of the scientist's success, he planned to murder him using a cobra. However, he himself was bitten by the cobra, which had been irradiated, and (similar to Spider-Man) Klaus gained the strength, flexibility, and reflexes of a cobra, and his bones became completely malleable. He then turned back to crime, and several times partnered up with Mister Hyde.