Japan has the lead in truly creepy monsters. The Kuchisake Onna is a young woman in a surgical mask who will approach young people and ask if she is pretty.
Answer No- Get killed with a pair of scissors.
Answer Yes- The Kuchisake Onna reveals a horrible slit mouth.
The Kuchisake Onna will then ask again if she is pretty.
Answer No - Get killed with a pair of scissors
Answer Yes - She will give you your very own horribly slit mouth.
The story was so frightening during the 1970s that the Japanese Govt. had to release a statement that the Kuchsake Onna did not exist.