Halloween Pumpkin Decorating Ideas

I need ideas for my schools Halloween pumpkin decorating contest. But you can not cut the pumpkin. There are four prizes for each class: the most creative, scariest, original and funny. Please help. Thank you

You can paint on a mask of "Scream" style, but perhaps a little too obvious.
Or, you could make it look like Leatherface from Texas Chainsaw Massacre, make a mask that looks a bit human skin, then attach it to the pumpkin. You could do a little chainsaw to go with it.

It's probably a bit late now since Halloween was yesterday but here are some sites that might give you some ideas (you can use for next year).

http://www.bhg.com/holidays/halloween/pu ...
http://familyfun.go.com/halloween/pumpki ...
http://familycrafts.about.com/od/pumpkin ...
http://www.countryliving.com/halloween/p ...