Jess Harley

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.

This version of Leatherhead made a cameo in All Tomorrow's Yesterdays, as the Eastman and Laird's Teenage Mutant Ninja Turtles witness alternate universes play out before them.

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.