A few years ago my wife dressed as a Catholic school girl (yummy!) I dressed as a priest (for a finishing touch I added dark sunglasses and a flask) (thumb)
Get some bucked teeth, a flannel shirt with a pillow inside for your stomach, an air gun, and a truck drivers hat. Walk around saying, "Need yer' tars changed?"
A couple of years ago my cousin dressed as roadkill.
Just get a crappy pair of pants and a shirt glue some crappy fake fur to it...spray it with a little fake blood and then lay the whole thing down and run over it with your car a bunch. I think I might have a picture...give me a sec i'll look.
I'm going as one of the Miller Lite beer refs. After my first plan to go as the Burger King fell through, this was something reasonable and we have a few variations. I'll be "roughing the palette" and another buddy will be the socks with sandals guy.