Fugly? Butt-ugly? Felony ugly? Coyote ugly? Trauma-inducing ugly? So ugly she’d scare a train up a dirt road? Ugly enough to make a funeral procession turn up an alley? So ugly she’d stop a clock? So ugly that when she takes a shower, the water runs down her back so it doesn’t have to look at her face? Her plastic surgeon took on a night shift? She turned Medusa to stone?
Something like that?
Uglier’n the dadgummed Wolfman hungover after a night o’ howlin’ round a fifty gallon still. Makes the elephant man look like a cheerleader. Uglier’n a fitty nine Chevy full o’ drunk Pelosis.
Possibly add:
So ugly she’d scare the maggots off a dead dog, so ugly she has to sneak up on a glass of water and so ugly she’d scare the stink off of $hit.
Whoopi fell off the ugly tree, hit every branch on the way down, upon hitting the ground her face caught fire, and was put out with an ice pick