MurkButt 

Similar to MudButt, only more violent and accidental death can occur.

guy1) Yo, i got a case of that MurkButt today.... like hardcore!
guy2) That sucks, bro. At least you made it out alive!

MurkButt by BCrunk!!! May 29, 2010

muckbutter 

Thick scum from the bottom of your lungs.

I just knocked over my cup of muckbutter

Muckbutter does not go good on eggs, it’s better on toast.

muckbutter by BlackLungJones September 9, 2023