Tod is the protagonist of Disney's 1981 animated feature film, The Fox and the Hound, and its 2006 midquel. He is a fox who becomes best friends with a hound dog named Copper, despite the fact that the two are supposed to be natural enemies.
Obviously, don't nominate any human characters. Hybrids like Cheetah or The Lizard are okay, as are shapeshifters with one set animal form (eg Professor McGonagall.)