Animal Hard Rock 1987.09.30 45 RPM Single Studio PolyGram Records Inc. 888-832-7 Robert John "Mutt" Lange Def Leppard's second US single from the "Hysteria" album Animal Hard Rock 1987.07.20 45 RPM Single Studio Phonogram Ltd. LEP1 (888-736-7) Robert John "Mutt" Lange Def Leppard's leadoff UK single from the "Hysteria" album