Horror movies based on true events are even creepier after you hear the real-life tale, and Nightmare on Elm Street is no exception. The story of the infamous, striped-sweater-wearing maniac was not just the invention of writer/director West Craven; the movie is actually based on real-life events. As is often the case with violent movies based on true stories, the real inspiration for Freddy Krueger is pretty disturbing.
In 1977, well over 100 Laos refugees inexplicably died in their sleep. The deaths of these perfectly healthy Hmong men have since been attributed to cardiac arrhythmia, but superstitious Lao people blame dab tsuam, an evil spirit that kills you in your sleep, and who appears in the form of a jealous woman.
The phenomenon was labeled "Sudden Unexpected Nocturnal Death Syndrome" (SUNDS), a term that was coined after healthy men all over the world began mysteriously dying in their sleep. If Freddy gives you nightmares, you don't even want to begin thinking about dab tsuam.