A funny joke about someone's mom, such as, Yo momma's so fat to get her through a doorway you have to grease it and hold a Twinkie in front of it. Or, yo momma is so fat when she got on the scale it said, "I need your weight not your phone number.
Bob: You got a fat momma
Jeff: Oh yeah? Well yo momma's so fat when she wears an orange jumpsuit and jogs up a hill people think the sun is rising!
Bob: Gotta admit, there are lots of good yo momma jokes in the world. You got that of the internet, didn't you