Mason Thames (Finney) said that after every take with The Grabber, Ethan Hawke would ask him if he was alright and would give him a "noogie" on the head.
The paperboy is a reference to Johnny Gosch, a paperboy from Iowa who was on a route with his dog Gretchen and disappeared. His dog was found later, but Johnny's disappearance remains unsolved to this day.
"I think it's fair to say he's my favorite actor I've worked with," said Scott Derrickson about Ethan Hawke. He recalled trying to convince Hawke to do Siniestro (2012) despite the actor's protestations that he didn't really like or watch horror. Hawke had been concerned it would be a dark experience, but Derrickson convinced him that it's actually a lot of fun making horror movies. Hawke had to be convinced once again for this film, as he believes that after playing a villain, the audience typically has trouble accepting actors as the hero again, so he told Derrickson the script would have to be great for him to sign on. Hawke called back that night after reading it, left a voicemail in the voice of The Grabber, and Derrickson knew he had him hooked.
The Grabber dons several creepy masks throughout the film, each exposing different portions of his face. They were designed by legendary prosthetic makeup artist Tom Savini. Mason Thames said that the first time he saw the mask, coupled with Ethan Hawke's bone-chilling performance, he was terrified.
The movie was delayed from its initial January 2022 release to June 2022 due to unexpectedly great preview showings. Once Blumhouse realized just how great early reactions were, they gave it a summer release date.