Horror movies about ghosts are as classic as it gets for seasonal Halloween scares, and a few of them are even spooky enough to warrant an R-rating. Despite their ubiquity as horror movie villains, ghosts rarely break the boundaries of PG-13, relying more on tension, gore, and eerie sights than straight-up gore, as is the case with many other horror genres such as slasher movies. However, a select few are able to break the boundaries of spectral scares far enough to be branded as true R-rated horror movies, suitable only for the most fright-forward audiences.