and *crazy as a peach-orchard boar; *crazy as a loon
Rur. acting as if insane. (*Also: as ~.) Tom: Susan says she's really the Queen of England. Bill: She's crazy as a betsy bug.Jill: David's a little eccentric, isn't he? Jane: Crazy as a loon, I'd say.What's wrong with Jim? He's acting as crazy as a peach-orchard boar.