Anything you can think of. The guy I was seeing back home went as God once. Just slapped a "Hello, My Name is:" sticker on his shirt and wrote "God" on it.

[Oz has been on her mind a whole lot since she became a Wolfwalker.]

If you're really stuck, you can always just use what you have on now, or pick out something else from someone selling costumes. I'm sure they'd be glad to give you suggestions too, if you want.