Yo mama is so ugly when she threw a boomerang it wouldn't come back
Yo Mama - Fix It Felix
Yo mama is so ugly Fix-It Felix said, "I can't fix it."
Yo Mama - Halloween
Yo mama ugly, she gets 364 extra days to dress up for Halloween.
Yo Mama - Vibrator
Yo mama so ugly, her vibrator went soft.
Dark Ages Insult
You should have been born in the Dark Ages, you look terrible in the light.