Some of y'all are just crazy! I just couldn't resist joining in!
"I ain't seen you in about a month o' sundays"
"Cold as a witche's tit outside"
"S#&t or get off the pot"
"He got as much hair as a bare headed yard dog."
(My grandmother's from North Carolina)
"Bald head as a tick"
"I'll knock your little rusty/dirty/ugly black a$$ in to East Jabip

"
(Where's that????)
"Hungrier than a hostage"
"Ain't nothin out past midnight but the devil."
And of course, an old favorite: "He needs Jesus."