Yo mama's so fat, the last time she saw 90210 was on the bathroom scale.
Yo Mama's so fat, if she buys a fur coat, a species will be extinct.
Yo Mama's so fat, the highway patrol made her wear "Caution! Wide Turns!"
Yo mama's so fat you have to grease the door frame and hold a twinkie on the other side just to get her through.
Yo mama's so fat, that she uses the refrigerator for her lunch box.