Horror films can be categorized into various subgenres based on style and content. Some common horror subgenres include comedy horror, slasher films, supernatural horror films, and those involving monsters or extraterrestrials. A horror hybrid combines elements of the horror genre with another genre, such as science fiction, comedy, or western, to create a mixed genre film. Examples given are Deadlands, which blends western and horror, and Alien, a hybrid of science fiction and horror.