I'm going to be Bob Ross, for those of you that don't know who that is, this link should ring some bells...

http://www.bobross.com/

Some of my better costumes from the past...

Bunch of grapes (green balloons safety pinned on a sweatsuit, kinda hard to get around)
Nun
One of my buddies just wrapped himself entirely in duct tape once...really hard for him to get around, and I don't even know how for sure he did it.