Itchy is the cartoon mouse from Itchy & Scratchy. He is a serial killer whose favorite victim is Scratchy. He almost always succeeds in killing Scratchy. There is only one known episode where Scratchy defeats him.
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.)
