When a friend/ex friend takes a shit in your penut butter. They then sir it up, and leave it alone until you decided to eat a peanut butter and jelly sandwitch.
Ron: God.. this sandwich tastes your nipples baby.. rawr
Wife: Dammit Ron, i gave you a Peanut Butter Poopwich
Ron: I didn't eat the crust do you want that back
A person, who leaves large dollops of "peanut butter like" shit on the inside of the toilet bowl. Usually found at the workplace, but can occur in the home. The peanut butter pooper is notoriously hard to identify, and is thought to be a supernatural/mythical being in Indian cultures of the American southwest.