Gremlins

A father gives his teenage son a strange looking pet named Gizmo for Christmas. There are only three rules about keeping a gremlin. 1. Don’t put them in bright light, 2. Don’t get them wet, and 3. Don’t ever feed them after midnight. After he violates some of the rules, it results in a surplus of gremlins, who soon turn evil and try to take over the town, doing whatever they please.