Cardboard monocle blog has this top 20 list of weirdest comic book weapons, like this one for example:
15 - Dung’s Dual Poop Cannons - Savage Dragon
One of the many throwaway villains that graced the pages of Savage Dragon, Dung is about as static as a character can be. He is a walking poop joke, armed (literally) with two sewage cannons. Where all that crap comes from remains a mystery, but the fact remains that Dung has one of the greatest weapons in comic history.
See the whole list: Link - via GorillaMask