[@BlackPanther]; hahaha, nahhhh totally not stalkerish at all honey..!

As for your idea, I get the impression that one might be talking about our lovely Cheshire Cat..! If my knowledge of disappearing characters proves to be up-to-date. Anyway; the idea that this magical character went to Earth and was one of the children is most definitely plausible..! We love adding more names onto the list of kids that are to come back with the guardians; the more the merrier we say. However, there are a couple of things I would like to point out...

[b][i]Those that are animals have a 'cursed' form?[/i][/b]

You are indeed only half correct on this one. While there are some (Scar, Odette, Naveen, etc.) who were indeed cursed with this form, there might be others (Bambi, Sher Khan, Cheshire, etc.) who were blessed with this form as some sort of shape-shifting magic. Each would have been given to them in a different way; whether it was bestowed on them, Rothbart (man with the animal fetish) cursed them with it, it might have been in their bloodline, or they were born with the gift.

As for the character being able to do magic on Earth... the only magic that's on Earth is what we have now, magic like what Domino and Houdini can do, and microwave popcorn. The only magic that's on Earth is the amulets given to the guardians; people as powerful as Elphaba might be able to conjure something... like maybe the tiniest flicker in her eyes, but she can't do anything with it until she gets back to their real world- same with Elsa, she's powerful enough that the cold doesn't effect her, but she has none of her snow or ice powers on Earth. So your character might be good a slight of hand, but there would be no magic until they get back to Rivenspire.