The Chcago Typewriter is a gun in the Resident Evil series. It only appears in Resident Evil 4 and is an unlockable weapon. It has infinite ammo and is based off the 1920's mob guns.
The appearance of the Chicago Typewriter changes depending on if Leon or Leon in his Mafia costume and Ada is using it.Normally the Chicago Typewriter's skin closely resembles an M1A1 Thompson, famous for its use in World War II, using a 30-round box type magazine. When used by Ada or Leon in the Mafia costume the Typewriter resembles the M1921 model with a foregrip and 50-round drum magazine.