Leatherhead

Leatherhead is a 12'4" or 7' mutant  alligator or crocodile (depending on which version).  He has appeared in all TMNT incarnations except for the movies and the live action series.

Mirage Comics
He first appeared in Tales of the Teenage Mutant Ninja Turtles #6. Originally Leatherhead was nothing more than an infant alligator which had somehow found its way into the sewers. While in the sewers, Leatherhead was found by a group of TCRI Utroms who decided to bring the creature to their headquarters. During his stay with the Utroms, Leatherhead was exposed to Mutagen which caused him to mutate into a humanoid and intelligent being.

Living with the Utroms, Leatherhead ended up being separated from his "family" when the TCRI building self-destructed. The now homeless Leatherhead was forced to live in the sewers where he was continually attacked by a big-game hunter called Mr. Marlin. During one attack by the hunter, Leatherhead met the Turtles. Aiding Leatherhead in defeating the hunter, the Turtles decided to allow Leatherhead to live in their old home.

Eventually two Foot Clan ninjas encountered an eye-patch-wearing Leatherhead in the sewers. Fearing that Leatherhead would kill them, the ninjas tried to get on Leatherhead's good side by promising to aid him in creating his Transmat Device. Accepting the help, Leatherhead and the ninjas set to work creating the Transmat, only to be interrupted by the Turtles. After a brief skirmish, the Turtles learned that the Foot ninjas were actually helping Leatherhead. Embarrassed by the incident the Turtles decided to aid the mutant alligator. Eventually the Transmat Device was complete, Leatherhead could finally reach the Utrom Homeworld. Unfortunately instead of teleporting Leatherhead, the device simply blew up in his face. This failure was too much for Leatherhead to handle and in a fit of rage, Leatherhead killed his two Foot assistants and vowed revenge on the Turtles, whom he blamed for wrecking his attempt to get "home."

Leatherhead later resurfaced in Volume 4. He makes an appearance at Master Splinter's funeral. He is then seen wrestling a mutated Raphael in the sewers before swimming off. It is unknown what his current relationship with the Turtles is, but Raphael's comment that he hopes he didn't hurt Leatherhead would make it seem as if they're at least on good terms.

He has also appeared in two issues of Tales of the TMNT Volume 2. In issue eight, a mentally unstable and delusional Leatherhead is discovered by Raphael to be building another Transmat Device. Leatherhead seems to harbor an insane grudge against Donatello, and nearly kills Raphael when he mistakes him for Donatello. Once the Transmat Device was finished, it suddenly kicked into operation and causes three Utroms to appear; these Utroms blast Leatherhead with a ray gun, and take him away, destroying the Transmat Device as they leave.

In issue twenty-three, the Turtles are recruited by the Utroms to save Leatherhead from a renegade group of Utrom radicals called "The Illuminated," the same ones who took him away in issue eight, in attempts to clone him into an army of mutants to aid in their world "cleansing" agenda. It is revealed that the Illuminated where secretly drugging Leatherhead, which caused him to subconsciously to build the second Transmat Device he was working on in issue eight, then wake up and remember little. It also caused his missing eye to heal and gave him a massive increase in size. The Turtles rescue Leatherhead, defeated the clones, and aided in the destruction of the Illuminated. Leatherhead returns to Earth with the turtles rather than going back to the Utrom home world. These events all take place between Volumes 2 and 4 of the Mirage series.

It is interesting to note that in the past, at several comic conventions, Leatherhead creator Ryan Brown has said he initially intended to kill the character off at the end of Tales of the Teenage Mutant Ninja Turtles Vol. 1, #6 by having the gator-man tumble into the underground gorge with the evil big game hunter but Turtle's creator Peter Laird nixed the idea opting to have Leatherhead survive and return to the sewers with the Turtles.

Brown returns to plot his creation after 19 years in the September 2007 issue of Tales of the TMNT. Out for a swim, Leatherhead encounters a group of aliens called Sigmurethites and attacks them. The alligator-man's Utrom guardian Dr. X also appears in this issue in a female scientist's exoskeleton.

Appearances

 * Tales of the Teenage Mutant Ninja Turtles Vol. 1, #6 - Leatherhead
 * Teenage Mutant Ninja Turtles Vol. 1, #45 - Leatherhead, Too
 * Teenage Mutant Ninja Turtles Vol. 4, #11
 * Teenage Mutant Ninja Turtles Vol. 4, #17
 * Tales of the TMNT Vol. 2, #8 - Virus
 * Tales of the TMNT Vol. 2, #23 - Attack of the Replicants
 * Tales of the TMNT Vol. 2, #38 - Triptyche
 * Tales of the TMNT Vol. 2, #50 - World's Deadliest
 * Tales of the TMNT Vol. 2, #58 - All Tomorrow's Yesterdays (Adventures version cameo)
 * Tales of the TMNT Vol. 2, #62 - Adventures in Bunnysitting
 * Tales of the TMNT Vol. 2, #63 - Monster Island

Image Comics
After two children are found slain and half-eaten in the sewers Leonardo comes to believe that Leatherhead may have been responsible. Tracking down Leatherhead, Leonardo was surprised to find the mutant alligator unconscious and bound. Before he could free Leatherhead, Leonardo was attacked by King Komodo and his Monitor lizard minions, the actual killers of the children.

Engaging King Komodo in battle, Leonardo successfully managed to kill King Komodo's minions, only to end-up being knocked unconscious with his hand bitten off. Waking up hours later, Leonardo managed to free Leatherhead and the two, with help from Michaelangelo and Casey Jones managed to defeat King Komodo.

Afterwards Leatherhead, his feud with the Turtles forgotten, introduced them to Dr. X, an Utrom left behind from when the TCRI building collapsed. Together with Dr. X and the Turtles, Leatherhead managed to assemble a new Transmat Device, unfortunately, energy projected from the device ended-up luring a group of Triceratons to Leatherhead's lair.

Engaging the Triceratons in battle with the Turtles, Leatherhead managed to viciously maul several of them. Unfortunately, while battling the last remaining Triceraton, Dr. X and Leatherhead's Transmat Device malfunctioned and transported Leatherhead and the unnamed Triceraton to parts unknown.

1987 Series
Leatherhead appeared in the 1987 series. In his first appearance, he forced the Punk Frogs as his slaves, but was thwarted by the turtles. He became a recurring villain from then on. In this series, Leatherhead has a Cajun accent.

Archie Comics
Leatherhead starts as an animal mutated by mutagen in all versions except from the Archie TMNT Adventures Comics, where he starts as a poor human named Jess Harley who lived in the swamps, and became transformed when the "witch" Mary Bones used the Turnstone on him. At first the Shredder lures Leatherhead to work with him until Leatherhead discovers that the Shredder is a villain. Leatherhead later becomes a wrestling hero at the Stump Asteroid and later a member of the Mighty Mutanimals. He and the other members of that group were killed before the end of the Archie Comics run with the Turtles characters.

Sometime before he was killed, Leatherhead appeared in a mini-series paired with Donatello. In the mini-series the brainy turtle and himself came equipped with extendable battle staffs and worked together to help save a young child in a savage land. In the mini-series he was very much the same character as portrayed in The Mighty Mutanimals comics.

2003 Series
Leatherhead appeared in the 2003 animated series. Instead of a villain, he was an ally to the turtles with a scientific mind like Donatello.

Leatherhead first made a shadowed cameo in "Secret Origins, Part 3" escaping from the TCRI building during the raid. He was first seen in the episode "What a Croc", where he was helping Baxter Stockman and had built the Turtlebot which was like the 2003 version of the 1987 series Metalhead. Unfortunately for Stockman, the doctor accidentally allowed Leatherhead to know he once worked for Shredder; since the Utroms had adopted Leatherhead he immediately got angry. Eventually Stockman bombed the location and Leatherhead sacrificed himself to save the Turtles. Later in season 3 it was revealed that Leatherhead had in fact survived the ordeal, but had been taken captive by Agent Bishop. The Turtles soon helped Leatherhead escape. He reappeared in a number of subsequent episodes as an ally to the Turtles, including the raid on the Shredder's building facing Hun.

Back to the Sewer
Leatherhead can be seen in Donatello's memory in the episode "Identity Crisis". Leatherhead appears in attendance for Casey and April's wedding in "Wedding Bells and Bytes". He is seen crying because weddings make him cry.

Video Game Appearances

 * Teenage Mutant Ninja Turtles III: The Manhattan Project: Boss (Sewer Level) -- Appearance is that of the action figure.
 * Teenage Mutant Ninja Turtles: Turtles in Time: Boss (Train Level) -- Before fight, says, "Oh goodie, fresh turtles for lunch." Appearance is that of the Original Cartoon design. In the remake, Re-Shelled, Leatherhead no longer has the hat and looks more sinister and realistic.
 * Teenage Mutant Ninja Turtles: The Hyperstone Heist He appears as the boss of the first level. Appearance is that of the Original Cartoon design.
 * Teenage Mutant Ninja Turtles 2: Battle Nexus: Boss character in the Turtles' old lair, as well as Battle Nexus mode.
 * Teenage Mutant Ninja Turtles 3: Mutant Nightmare: Leatherhead is shown in the background in a cutscene near the end of Episode 1. There is no reason given why he is there in space with the Turtles, Casey, and April. In reality, this is because the scene was taken directly from the cartoon, where he was with them for some time.

Trivia

 * Ryan Brown, at different convention appearances, has stated that his character Jess Harley is an homage to his favorite actor, Lance Henriksen, and is named after two characters from his favorite films, Jesse Hucker in Near Dark and Ed Harley from Pumpkinhead.