Irena is the main character of the 1942 horror film Cat People and its 1982 remake. She is a Serbian woman who believes she carries a curse that will cause her to turn into a large, predatory cat when aroused.
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.)
