The story on which the film is based, "The Bridge to Body Island," has a much more complex mythology for the Bye Bye Man: He was an albino born in New Orleans in 1912 who ran away as a child and became a derelict who lived in a train yard. After going blind he began murdering people and cutting out their eyes and tongues, which he sewed together and brought to life using voodoo. The resultant creature became the Bye Bye Man's literal seeing-eye dog, helping him hunt his prey. Several elements from the story- notably the dog and the motif of trains-- were retained for the movie, though their purpose is left more elliptical.
Previously rated R by the MPAA for "bloody horror violence, language and some sexuality."
Doug Jones, who plays the title character, previously played Slender Man (who has similar abilities) in Always Watching: A Marble Hornets Story.
Doug Jones who plays The Bye Bye Man is accomplished character actor. His other work includes the Ice Cream Man in Legion, Abe Sapien in Hellboy, Cochise in Falling Skies and most recently as Saru in Star Trek Discovery.