AceShowbiz - Coming up from different sources, both "It" (2017) and "A Nightmare on Elm Street" have a similar underlying idea which is a supernatural entity that preys on young people. In the adaptation of Stephen King's novel, the creature comes in the form of Pennywise the Dancing Clown as the author believes it attracts children, yet for some others it is terrifying. "A Nightmare on Elm Street", on the other hand, is about the evil force that manifests itself through nightmares.
While Pennywise was purely King's fictional creation, similar events like those in "A Nightmare on Elm Street" creepily occur among people from a mountainous province of Laos called Hmong. Young males in the community are affected by "oriental nightmare death syndrome" or what is known as "Sudden Unexpected Death Syndrome", where the victims die of fright from their own belief of what happens in their dreams. It is believed that a spirit known as "dab tsuam", which takes the form of a jealous woman, takes men to the spirit world when they sleep.