mouse peeking 

description of one's need to use the crapper, wherein the need is so bad, a turd is poking our of your arse just as a mouse peeks out of its hole.

Oh man. I gotta go so bad I've got a mouse peeking!!!

mouse peeking by anonymous April 8, 2004

Moose Peekin'

Used to describe the way a poo log looks (like a moose head that's peeking out). This usually occurs when one is in dire need to use the bathroom.

"How much longer is he going to be in the bathroom? I've got a moose peekin' here!"

Moose Peekin' by Bbbllgggh August 28, 2005