Deep in space, a penal colony located on a remote asteroid has just captured some Crites- small, porcupine-like creatures. Somehow, these creatures of voracious appetite escape from the asteroid in a space ship and land on earth, in search of something to satiate their craving-food, preferably humans.
In pursuit are two taciturn bounty hunters who can change their faces into anyone they choose. One of them, Ug, will choose Johnny Steele's face, a rock singer number one in the charts, while the other still hesitate and keeps his basic face, waiting for more.
The Crites land close from the brown's farm and begin to eat everything. Noises attract the attention of Jay and his son Brad. They discover with horror that a cow of the herd has been devoured. While directing to the Brown's farm, the Crites profit to devour Jeff, the Sheriff's assistant. On place, the telephone no longer functions and it is the same for electricity. While he is going to re-establish the disruptor in the cellar, Jay is attacked by one of these curst beast. His wife Helen and Brad save him just in time.
Fortunately, the extra-terrestrial bounty hunters seeking for the Crites land their turn on earth and can already observe damages. By approaching Jeff's car, the second hunter in lack of inspiration profits to use the policeman's face. With the appearances of a Sheriff's assistant and a rock star, our two bounty hunters seek for their preys.
Meanwhile, the Browns have enclosed at home and trenched in Brad's bedroom struggling for the best against the assailant. Crites have already devoured April's boyfriend, Jay's daughter, and does not cease to enlarge. In a last chance attempt, Brad straddles his bike and rides to seek his neighbors's assistance. On course, he meets the two Crites's hunters he lead at his home.
The bounty hunters begin an explosive but efficient household. But the largest of them has kidnapped April. Brad goes to her research that lead him near the spaceship of the beast coming from outer space...
Spoiler ! the end of the story is revealed below…
He enters the spaceship, delivers his sister then traps the ship before he gets out. The spaceship takes off and explodes during its flight. All Crites have finally been killed. Before leaving, Johnny gives Brad a little transmitter while saying him "Call me". When Brad operates it, the all destroyed Brown's farm reconstruct itself automaticaly. But, in the coop, three small eggs nobody noticed are ready to flower.
The Critters project had to be rebuild because there was too much resemblances with Gremlins, the Steven Spielberg's production, premiered just before it. Shots happening in a kitchen, during which Critters ravage everything before to be victim of domestic machines have been cut. Similarly "nice" shots that made Critters nice creatures have been suppressed. The very first version of Critters was far more bloody, but in order that the film is authorized to the thirteen years old public, producers have asked to suppress the bloodiest shots.