Garrett is not an animatronic, but a character in the Five Nights at Freddys movie. He is Mikes younger brother who was kidnapped and killed by William Afton, a serial killer who worked at Freddy Fazbears Pizza. William Afton hid his victims bodies inside the animatronic characters in the restaurant. While Garretts ghost does not appear in the movie, there are theories that he may be possessing the Puppet or have some connection to Balloon Boy.