Definitions by Solid Steak

laying an egg 

to poop your pants; to fart; a stinky bowel movement.

"Jingle bells,
Batman smells,
Robin laid an egg"

Clearly, by "laying an egg," the writers of this song meant that Batman was smelly because Robin had shit his pants in the Batmobile.

laying an egg by Solid Steak April 17, 2007