Hilarious Big Mamma Oversized Underwear. Why not give some Big Momma Undies, so hugely oversized it's enormously the best prank gift you can give. Fitting size 98 to 100 and made of 100% polyester fabric. Caution: Stay back, this will be a wide load! Hand wash with cold water...possibly in the bathtub. It will be a sure laugh getter at your family or work party.