"Curt Connors was a gifted surgeon who went into a war to help his country. He performed "meatball" surgery on wounded GIs, but his arm was injured in a blast and had to be amputated. He eventually became obsessed with uncovering the secrets of reptilian regeneration, and studied reptilian biology extensively. Connors finally determined a serum taken from the DNA of a reptile. He had successfully regrown the missing limb of a rabbit, and, despite the warnings of his wife, chose to test it on himself. Connors ingested it, and his arm did indeed grow back. Unfortunately, it had one side effect: Connors was subsequently transformed into a reptilian monster and a regular enemy of Spider-man – Lizard!"