Ever since The Exorcist, a kid with a psychic link to arcane evil forces has appeared in many a horror film. The Omen, The Shining, Poltergeist, and even this year's Ouija: Origin of Evil presume that children are friggin' terrifying.
Children are not actually terrifying, of course. Twelve-year-olds pee on the floor, scream profanities, and throw up on their psychiatrists every day, and no one thinks anything of it. But in 1973, the moment the demon Pazuzu -- inhabiting the form of Regan MacNeil (Linda Blair) -- replies to Father Karras (Jason Miller) that his mother's maiden name is a bright-green pile of retch, any audience member who had yet to question the inherent goodness of children certainly rethought it.
"I had really had enough of the vomit," Blair, who was 13 at the time of her career-defining role, told IGN in a 2014 interview. "I'm not going to lie. It was warm, stinky, smelly, thick, gooey. It was the one thing that just was, like, pushing me over the edge."