Sophie Thatcher “had a lot of different fears” growing up.

While chatting with ET Canada to promote her new horror/mystery, “The Boogeyman” — a classic childhood fear — the actress, who portrays Sophie in the film, listed a number of supernatural creatures and slasher film characters she was most afraid of as a kid.

“I was scared of that mermaid in [‘Harry Potter and the] Goblet of Fire,'” she began, referring to the merpeople living in the Black Lake in the 2005 film.

“Chucky, Slenderman,” she continued, “and, like, basically any ghosts. I thought I saw, like, witches in the mirror. Lots [of fears].

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“I had a great big imagination,” she added.

Speaking about “The Boogeyman” — 20th Century Studios’ adaptation of a Stephen King short story — Thatcher, 22, said she’s proud to be part of a film that’s so terrifying that people can’t even finish watching the trailer.

“I mean, that’s the goals and horror. It feels great,” she said.

The “Yellowjackets” star thinks it’s the “built-up tension” that’s making people so scared.

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“I think you really feel for the characters. They feel realistic, and you can easily put yourself in Sadie’s shoes. So I think just going into that, you feel more vulnerable as a viewer,” she elaborated. “It’s the silence that’s built and the jump scares aren’t just jump scares. It feels fuelled and they just feel very effective.”

Thatcher also applauded the film creators for doing “a good job” on producing such a scary monster.

“The Boogeyman” creeps into theatres on June 2.

Check out the trailer below.