A phrase used to designate your guess who the highest ranking redneck in any group of rednecks is. Can be used to deem the "leader of the pack" or one with the highest of redeck credentials.
Look at that man over there. His mullet has to be at least 9 inches in the back. He has to be the ultimullet!
by robulastage May 16, 2011
a mullet haircut so extreme that it is nearly shaved on the top and sides and the back extends down past the wearer's ass. can also be used to describe the wearer.
Dude, check out the ultimullet on that drunk-ass!
by weeZy August 12, 2002