Gremlins

A young boy receives a new "pet" for Christmas called a Mogwai. In order to take care of the furry creature, he must follow three very important rules: Never expose it to bright light (which will kill it), never get it wet (which will make it multiply) and never, ever feed it after midnight.

When the rules are unintentionally broken, it unleashes many of the mischievous monsters across the town.