Question on the whole over-done special abilities thing.

I'm working on my first character and I know that shapeshifters/animagus' are really overdone, but something I was thinking about was having her be exceptional at Transfiguration and that one of her own personal goals be to become an animagus. Does that still seem like a better way to go about the whole "I want to be an animal" thing, or would I just be beating a dead horse/human hybrid?