After banging a broad (or whatever preference) in the ass, a shit worm forms in your cock. Whether before or after you cum, the bitch gets down and sucks the shit right out of your dick. That's the black snack.
A condition caused by excessive lint (commonly present in a new pair of underwear) clinging to the scrotum after the first use. The fuzz will fuse with ball sweat or Fermunda Cheese giving the appearance of an African-American's scrotum.