Horror films often deal with viewers' deepest fears through stories involving the intrusion of evil supernatural forces into the everyday world. Common horror elements include ghosts, monsters, demons, and serial killers. While horror aims to provoke negative emotions through frightening scenes and themes involving the macabre and supernatural, not all supernatural-themed movies are necessarily horror. Comedy also focuses on individual stars but can contain social commentary, and blending horror and comedy genres could have similar elements to films like Scary Movie or Shaun of the Dead.