Leatherhead (TMNT 2012)

Leatherhead , is a character of of Teenage Mutant Ninja Turtles (2012). He is an ally to the turtles in this incarnation, and has also become Slash's second-in-command in the Mighty Mutanimals.

History
Leatherhead was a baby alligator that was owned by a kind boy until the boy's cruel parents found him and flushed him down their toilet into the sewer. He was discovered there by the Kraang, taken to their dimension, mutated, and experimented on. After suffering long and brutal torture, Leatherhead escaped back through the portal that connected Earth to Dimension X with a piece of the Kraang power cell. Leatherhead took up residence in the sewers, contending with his violent temper and protecting the power cell at all costs. He soon comes across the Turtles, befriending Michelangelo, but after fighting several times alongside his new friends against the Kraang, sacrifices himself to defeat the Kraang and is sent to Dimension X. During his absence, an illusion of Leatherhead is conjured by Sir Malachi during "Mazes and Mutants", played up as the typical fairy-tale dragon for the Turtles to defeat.

Though only a year passes on Earth, several decades pass in Dimension X, and Leatherhead returns in "Into Dimension X" considerably grayer, leaner, and older. The Turtles enter Dimension X and are elated to reunite with their old friend. Together, they stymie the forthcoming Kraang invasion of New York, and though Leatherhead once again tries to sacrifice himself to save the Turtles, Mikey is able to bring him back home to Earth. Though the Kraang's invasion has been halted for many years in Dimension X, they nevertheless invade Earth within the next few days. Leatherhead personally came to Splinter's aid against the Shredder, violently thrashing him around in his powerful jaws. However, the Shredder hit Leatherhead's pressure points to subdue Leatherhead's superior might, and pummeled him into the sewers.

Half a season later, Leatherhead returns as the second-in-command of the Mighty Mutanimals, a ragtag group of mutants formed by Slash that have been fighting the Kraang invasion since the taking of New York. Leatherhead is overjoyed to be reunited with his friends, especially Michelangelo, and takes part in the battle to evict the Kraang from New York. In "Clash of the Mutanimals", Leatherhead and Pigeon Pete work to free their brainwashed comrades Raphael, Slash, and Rockwell when the Shredder uses them as test subjects for a mind control serum. Leatherhead got a second chance to fight Shredder, but the combined might of the four Turtles and four Mutanimals was only enough to fight Shredder to a draw. In the third-season finale "Annihilation: Earth", Leatherhead nearly attacks Bishop, a defected Kraang, and does not come to trust him until after they work together to take down the Technodrome. Leatherhead takes part in the battle against the Triceraton Empire, but the heroes are unable to save the planet, and Leatherhead is last seen trying to take Rockwell's hand as they are all sucked into a black hole to their deaths. Leatherhead's death is undone thanks to the efforts of the Turtles and Professor Zayton Honeycutt, who go back in time and ultimately prevent the Earth's destruction and Leatherhead's death.

When the Shredder mutated into the Super Shredder, Leatherhead put up a ferocious fight against him once again, and later took part in the clash against the returned Foot Clan. Leatherhead personally killed Rahzar by grabbing him in his jaws and dragging him to the bottom of a river, drowning him. When Splinter fell in battle against Shredder, Leatherhead and the other Mutanimals attended his funeral in the fourth season finale "Owari". Leatherhead and Karai were later summoned by Mikey to help battle Kavaxas' apocalypse in "End Times", and Leatherhead had the opportunity to bid farewell to the deceased Splinter's spirit once Kavaxas had been defeated.

In The Big Blowout, Leatherhead and the other Mutanimals teams up with the Turtles, April, Casey, Karai and Shinigami to defeat Bebop and Rocksteady, who are recruited by Krang and 1987 Shredder.

Trivia

 * In Leatherhead's first two episodes in the first season, every time he loses control of his anger around the Turtles, he tended to grab Donatello by the face and shake him like a rag doll.
 * Leatherhead has a scar on the upper left side of his chest. He received it when he stole the power cell from the Kraang.
 * When he is angry, Leatherhead's eyes are covered with white membranes, the nictitating membranes, that in normal alligators, crocodiles and relatives, protects the eyes when they are diving.
 * His head looks much more like that of a crocodile than an alligator.
 * Leatherhead's rollover is an actual crocodile/alligator movement known as the 'death roll'; it is something of a signature move that is primarily intended to tear their prey apart.
 * In Into Dimension X!, it was revealed in one of Michelangelo's flashbacks that sometime in between the beginning of It Came From The Depths and Leatherhead's second appearance in TCRI, there was at least one time Leatherhead and Mikey slept together on the floor of the common area. This briefly-shown tepia-toned ambient-lit scene showed them both sleeping on their left sides against the floor grate, Mikey's back spooned into Leatherhead's front, with Leatherhead's long trail curled around Mikey's other side.
 * Leatherhead was introduced with green scales, but since Into Dimension X!, his scales have gone grey from age. In the new opening sequence that premiered with the episode, Return to New York, Leatherhead is shown with his youthful green scales in the scene where he jumps from the rooftop of the Party Wagon to the rooftop of Bebop and Rocksteady's van. But when he makes his return episode appearance in Battle for New York, Part 1, his scales are still grey. Oddly enough, during the entire episode of "Requiem", his scales were green.