turtle tail 

Having to take a dump so badly that the turd is starting to wiggle its way out of the gate. Incorrectly defined on urbandictionary.com as turtle head, "turtle tail" is a much better descriptor for a tapered turd that has quietly poked its way out of your posterior.

Dude, can you pull over at that gas station? I've got a turtle tail.

turtle tail by mig May 7, 2005

Turtle’s Tail 

The opposite of a turtle’s head. Having made it to the lavatory, dropped a big one and flushed. The turtle’s tail can be found lurking on the consumer side of the U bend.

Dad: Bloody hell! Who’s left this turtle’s tail in ‘ere!

Turtle’s Tail by Dfsjdjdj December 5, 2020

turtle tailin

Like prarie doggin, it is when a turd is peeking out of your bunghole, like a turtle's tail coming out of its shell.

"Dude, I need a bathroom."

"Why?"

"Because I'm already turtle tailin it."

turtle tailin by JonnyCakes August 19, 2007