Butt troll
One who's conception is the result of an accidental leakage and transfer of semen from the soon-to-be mother's anus to her vagina. Assuming the feces covered sperm reach an egg cell and successfully fertilize said cell, the outcome will be a rather poor excuse for a human child. This child (Butt Troll) will be forever ridden with terrible hygiene and an uncommonly low level of intelligence.
Brittany's parents should have paid a little more attention to their post-anal-sex clean up process. That girl is smelling up this entire building. I guess I wouldn't expect much else from a Butt Troll though.
Butt Trolls
Mythical creatures used to explain gas, rumbling and other noises from the gut and rectal areas during periods of stomach discomfort, most notably as part of a hangover.
Tom: "Dude, was that a fart?"
Jerry: "I think it was the Butt Trolls"
Jerry: "I think it was the Butt Trolls"