ElfGrove

(EDIT: Fixed the link. Sorry, you guys not on his friend's list will have to miss Silas's awesome art of Barbie pwning a Bratz.)
That's Right Bitch!
No sluts in the doll house PLZKTHX.

But seriously. I code for a living. I know this deal. You sign a bunch of stuff when joining this sort of company, and anything you create within your professional field and/or on company time is legally theirs. You sign that paperwork. It's all pretty cut and dry.
Heck, if I wrote a fantasy novel right now, I'd have to go through checks and red tape with the company to ensure it was unrelated to my work before I could ensure I legally owned all of the content and could publish it. That's how this works, and I know it going in. I read my contracts.

Besides. I hate those Bratz dolls.