My son went to Las Vegas last weekend and got a $10 coupon from his hotel to play the slots in the attached casino. He ended up with $0.25 and decided to just cash it in for the heck of it. The lady at the counter must have been annoyed to have to deal with such a small amount, since she gave him the following:

I've seen coins that have gone through the laundry before, but I can't imagine what could have caused this apart from deliberate disfigurement. I don't imagine any vending machine would accept this, and I'm not even sure if it's even still legal tender at this point...

[And, no -- I don't recall the name of the hotel he was staying at.]