grease burger

The turd that is left behind in the toilet when someone forgets to flush the toilet after dropping a deuce. It is usually several minutes or hours before it is discovered and typically not pleasant to look at.

John: Did you hear about what happened to Leavitt?

Jason: No!

John: Teresa left him and took everything. All she left was a grease burger in the toilet!

OR

Trey: Hey! Whoever left this grease burger in the toilet needs to come flush it.