A Turtle on the Outside, a Wolf on the Inside

Before Yoshi got the turtles from the Pet Store, Leo was found playing with the manager's dog, who was told to be a wolf-hybrid. Right before Yoshi took the turtles away, Leo ate some of the canine's fur and when he got mutated, the mutagen somehow enhanced the inside of his body to match a wolf's behavior and abilities. NO T-CEST, LEORAI or APRITELLO!