Gremlins

Gremlins is a 1984 American comedy horror movie written by Chris Columbus and directed by Joe Dante. 
The movie is about a kid who receives a strange creature called a "mogwai" as a pet, which then turns other creatures who transform into small, destructive, evil monsters. The movie stars Zach Galligan and Phoebe Cates, with Howie Mandel. Steven Spielberg was the movie's executive producer.
It was followed by a sequel, "", in 1990. 
Despite being a critical and commercial success, the movie had mixed reviews. This movie is one of the reasons why the PG-13 rating was created because it was made as a family movie, but had some violence and bloody scenes.