Gremlins (1984)

A gadget salesman is looking for a special gift for his son and finds one at a store in Chinatown. The shopkeeper is reluctant to sell him the "mogwai" but sells it to him with the warning to never expose him to bright light, water, or to feed him after midnight. All of this happens and the result is a gang of gremlins that decide to tear up the town on Christmas Eve.