Dr. Curt Connors, a one-armed biologist, drank a serum that gave him a reptile's ability to regenerate limbs. But the serum also turned him into a savage lizard-like creature with a whipping tail.

noun

any of a suborder of reptiles characterized by a long slender body and tapering tail, a scaly skin, and four legs, sometimes merely vestigial [a trace, mark, or sign of something that once existed but has passed away or disappeared]; most species live in hot, dry regions, as the gecko, horned toad, chameleon, and iguana

Chameleon
Mondo Gecko
Toad