The PM-63 RAK (short for Ręczny Automat Komandosów — "commandos' hand-held automatic"; the abbreviation itself means crawfish or cancer in Polish) is a Polish 9mm submachine gun, designed by Piotr Wilniewczyc in cooperation with Tadeusz Bednarski, Grzegorz Czubak and Marian Wakalski. The RAK combines the characteristics of a self-loading pistol and a fully automatic submachine gun.