Alligaturtle is a mutant on the island that had the body an alligator (with only two legs) and the shell of an snapping turtle. He has appeared throughout the series as a background character.
He was first seen hanging around Two legs-Joe during the construct (or reconstruction) of the city, the mutant carrying a pot of glue on his shell. (Bowled Over)
He is very similar to Terrorgator, a fuzor from the Beast Wars Toyline.
He was one of the mutants that the doctor had planned to choose to turn into a super soldier. (Sergeant Snuggums)