yo mama jokes

Yo mama jokes are a form of ritualized insult where the target is the listener's mother, typically exaggerating her weight, age, stupidity, or poverty: Yo mama so fat she has her own zip code.

The format is formulaic—"yo mama so [adjective] that [absurd consequence]." The jokes belong to a tradition of competitive verbal sparring where wit matters more than the actual insult.

Nobody's mother is really being attacked; the game is to craft the most outlandish comparison.