Green’s Dictionary of Slang

(orig. US) a fool, one who is out of control.

1970		E. Thompson Garden of Sand (1981) 187: They’ll lock his crazy ass up one of these days, talking like that.
1974		V.E. Smith Jones Men 75: Some crazy ass done fucked with his dope?
2011		F. Bill ‘Officer Down’ in Crimes in Southern Indiana [ebook] Who the hell did this crazy ass think he was, shooting a conservation officer.