When anal sex occurs and the fuckee has not cleaned their anal cavity properly (i.e. a euphemism for shit).
Dude! Why didn't you get all that mud bunny out of your ass before you let me put my dick in?!
by folkyboy August 02, 2008
1 more definition
Hardcore female mountain bikers.
"Those are some serious mud bunnies." - said after watching 3 women fly past you after they clean an enormous drop that you just chickened out on.
by sir laughalot December 21, 2012