Phantasm (1979)

Mike, a young teenage boy who has just lost his parents, is afraid to lose his brother. This fear causes him to follow his brother to a funeral, where Mike witnesses the Tall Man lift a coffin on his own. Mike decides to investigate and discovers a horrible world where the Tall Man, along with his flying spheres, shrink the to half their normal size and reanimate them as slaves. It is then up to Mike, his brother, and Reggie the ice cream man to stop the Tall man.