The giant mutant snapping turtle ally in the Teenage Mutant Ninja Turtles franchise is named Slash.
Slash is a mutated snapping turtle whose character varies between continuities. In the 1987 cartoon, he is associated with Bebop and is portrayed as a powerful but impulsive turtle with a preference for palm trees.
Later versions give Slash more sympathetic motivations and stronger connections to the main turtles. The character’s species and physical design distinguish him from the four protagonists, who are generally depicted as smaller, more streamlined turtles.
Slash is often confused with Leatherhead, another major mutant ally who is an alligator, or Tokka, a snapping-turtle mutant from Teenage Mutant Ninja Turtles II: The Secret of the Ooze. Their animal identities and story roles differ.