Sorry for any confusion this may have caused!
List of (Reasonable) Potential Killers
The Creeper ( Jeepers Creepers)
Annie Wilkes ( Misery) - Haha... No, seriously, this chic freaked me out.
Iris - 30 days of night
Old Woman - The Devil
Pale Man / Fauna
Otis B Driftwood
Hal 9000 ( Computer controlled killer)
Regan McNeil/Possessed character
The Craft/ Witches or Wiccan powered
Margerite White - Carrie
Honorable mention for survivors. Ash from Army of Darkness please
Link to Wikipedia with other not-as-popular selections