Originally, the producers couldn't get the rights to use Taylor Swift's "Shake it Off" in the film, as they were denied by the record label. Lupita Nyong'o is a big fan of the song and saw it as pivotal part of the screenplay, which led her to personally get in touch with Swift to explain why the song was important to her and the narrative, after which Swift granted her the rights.
Film is dedicated to Abe Forsythe's son Spike, whose first day of kindergarten inspired parts of the story.
During the end credits, a song is sung by Teddy McGiggles(Josh Gad).
The school children central to the movie do not become little zombie monsters themselves, the films title comes from the lyrics of a song sung by their teacher to help keep them calm.