A joke consisting of the specific phrase, "Yo mama (is) so---". It is an amusing, yet degrading style of joking. Use it when you are mad at someone!!!
Yo mama be so fat, she got baptized in Sea World.
Yo mama so greasy, she sweats Crisco.
Yo mama so big, when she was floating in the ocean, Spain conquered and claimed her as their New World.
Yo mama so big, she uses a paint roller to apply lipstick.
Yo mama so greasy, Texaco buys oil from her.