Mud But is the way you feel after you've had McDonalds for breakfast.
I just had a B.L.E.T. Bagel from McDonalds and Now I've got MudBut. I'm pissing through my asshole.
by Paul Maletic December 05, 2008
when one farts and it sounds like they shit themsleves.
Justin must have mudbut, because it smells like shit.
by Jrue January 29, 2009
A Mudbut is a small mythical woodland creature found in rural central Pennsylvania. This creature is slightly smaller than a cat and extremely fuzzy. To see this animal would remind you of a koala bear mixed with a household cat. It gains its name by the sound it makes which is in a very highpitched light voice it say "mudbut"
Holy crap there's a mudbut!
by big willy mcClain April 27, 2006