mean grumpy 

n. is a poop that is especially bad and stinks up the whole bathroom, it is often paired with lots of grunting and pushing.

dude, i just dropped a mean grumpy in the bathroom.

mean grumpy by jojoboneroo February 7, 2006

Mean Ol' Grumpy 

Large, nasty bowel movement.

Man, my stomach hurts. I need to take a mean ol' grumpy!

Mean Ol' Grumpy by Husker Guy November 4, 2016

Mean mr. Grumpy 

A fart characterised by an extraordinary long low growl when releasing gas from the rectum. The name derives from the creators of such farts, grumpy old men. also because the fart seems to mimic the sound of a grumpy old man.

Buuuuurrrrttt! Fuck i just left a mean mr. Grumpy

Mean mr. Grumpy by Paul Merr November 5, 2018