15. He Became A Werewolf
During a battle with a villain known as Nightshade (who dubbed herself the "Queen of the Werewolves"), Captain America was injected with a serum which turned him into a werewolf. Despite his pretty major physical change, Cap remained himself in terms of personality, and this new look lasted for a few issues before "CapWolf" as he became known was cured and returned to his human self. One of the most enjoyable moments in this strangle little story was when he came into contact with Wolverine - who was in a berserker rage at the time - and swiftly dealt with the X-Man by going into an animal rage of his own.