Lou is a fictional character who was originally created for Batman: The Animated Series. He is one of Harley Quinn's pet hyenas. Along with Bud, he is named for the comedy duo Abbot and Costello.
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.)
