Chunks of a fart that are not exactly air. They can be soggy or chunky, and often smell like a dead newborn that just crawled out of a dead skunks butthole. Having wind biscuits can commonly result in a change of underwear; but not a change of pants
During the naked bike race, 1st place, jimmy, decided to release some gas. Unfortunately for second Second place (billy) the fart contained poop flakes from Jimmy's unsatisfactory attempt at wiping which sputtered back behind him.
Billy- Jimmy! You butthead! You got your wind biscuits on my chin!