Annabelle, from the film Annabelle: Creation (Picture: Warner Bros)
Whether it's a description of evil spirits as it pertains to Catholicism, the study of possession in Islam or older pre-Abrahamic religions, this page is guaranteed to freak you out whether you are religious or not.
Slender Man is a bit of a modern-day Sadako from The Ring. A creation of the internet via a creepypasta Internet meme, it became something of a cultural phenomenon. He is thin, unnaturally tall with a featureless head and wears a black suit. He is commonly associated with stalking and traumatising children.