If brains were dynamite he wouldn't have enough to blow his nose.
If a bird had his brains he'd fly backwards.
He's so ugly no fly'd ever land on him.
Looks like he's been chewin' tobacco and spittin' in the wind.
When he was a baby he was so ugly they fed him with a slingshot.
She's so fat that if she had to haul ass she'd have to make two trips.
[As tearful as] a child that's lost his chewing gum on a henhouse floor.