Fuck, Loompa would be awesome, with the right writer and director.

You could run with a different perspective on almost any of his grotesque villains (the giants, or Boggis, Bunce and Bean) where they grow up abused by people (like Dahl cough cough) who mock and belittle them for being fat or thin or ugly, and so they become abusers. It wouldn't be that original (Napoli's The Magic Circle is from, hell, 30 years ago now, and Wicked is almost as old) but you can do good things with that. But your ideas are all better.