Something to say when a person is being a dumbass.
Having your head shoved so far up your butt crack, you could wear it for a hat. Deriative from the popular insults "to have your head up your ass" or "ass hat".
God damn, you're a crack hat!
Like a beer hat, but with crack cocaine
James: I just pictured you in a beer hat
Lucy: Why not a crack hat?