To take jwunderdog's one step farther..
If a gal was really ugly - it's Fugly
Fat girl descriptions:
She's got some junk in her trunk.
She's a hungry hungry hippo.
Body by Cake (remember Body by Jake)
Cellubutt, Jellopants, lardass
And if a friend went out with a fat chick,
he would be a chubby chaser, cow wrangler and a date would be to 'free willy' - in more ways than one.
And finally, "I wouldn't take her home, she may eat you and we'll never see you again. "