Screenwriter Dennis Paoli previously adapted H.P. Lovecraft stories for the 1980s films "Re-Animator" and "From Beyond," which both starred Barbara Crampton.
This film is an adaptation of the 1933 short story "The Thing on the Doorstep" by H.P. Lovecraft.
The Miskatonic University is mentioned a couple of times throughout the narrative, placing this movie within the universe created by H.P. Lovecraft.
The two psychiatrist characters were both male in the original script.
Judah Lewis / Asa wears a T-shirt from the band Faith No More. Director Joe Lynch was the director for the Faith No More music video for the song Sunny Side Up in 2015.