Frog With Pants
A person who has no ass to fill out the back of their pants, making it seem like a frog got up, put on a pair of pants, and walked away.
Guy: Hey Joe look, Tito's ass looks like a Frog With Pants on.
Joe: Hahahahahahahaha
Tito: Fuck You
Joe: Hahahahahahahaha
Tito: Fuck You