Achievement for discovering the demon-possessed cannot be teleported, rewarding unlimited pea soup.
Demons Hate This One Trick! is an achievement Carl unlocks during his box-opening session in The Ceasefire. Its text mocks the discovery — "Hey, what do you mean you can't teleport the demon-possessed?" — and jokes that if Father Merrin had known, The Exorcist would have been a much shorter movie.
Carl earned it when Samantha teleported an entire beach to their position, including the shells of all the demon-possessed zombies, an event that helped kick off the chaos at the end of the previous floor. The reward permanently changes the team's Food Boxes so they all now give an unlimited supply of Pea Soup — the first of two food-box modifications Carl receives in the same session, a coincidence he does not believe is a coincidence.
Achievement documenting the demon-possessed teleport immunity, and a permanent food-box change.