Leatherhead is a mutant alligator. He is generally an ally to the Turtles, but sometimes is a villain and their enemy.1987 cartoon - Leatherhead was a normal alligator who got mutated when Shredder and Krang dumped mutagen into his Everglades swamp. He acts as a villain in this show, hunting and fighting the Turtles. He possesses bear traps and crayfish, and speaks in a Cajun accent.2003 cartoon - Leatherhead was originally an exotic pet who got flushed down to the sewer. He ended up in an Utrom base, who gave him mutagen and turned him into a humanoid gator with extreme intelligence. He befriended the Turtles, especially Michelangelo and Donatello, and serves as their ally with developing gear and chemicals to aid them.2012 cartoon - Leatherhead was originally raised by a boy, but his parents discovered and him flushed him down the sewer. He was found by the Kraang and taken to Dimension X; there they experimented on him, which gave him intelligence, but also gave him berserker rages from their abuse of him. He eventually escaped and made it to Earth, where he befriended the Turtles (especially Michelangelo). He eventually became a member of the Mighty Mutanimals, a group of heroic mutants.