When Davis wakes up on the stretcher and he winces in pain, this was due to Sam Witwer unknowingly having appendicitis while filming.
When Jimmy met Davis looking to get more info on the killer, he said the best description a witness gave was that the killer was "a monster with bony eyelids." In the comics, Doomsday is exactly that.
Two guest actors in this episode have appeared in Supernatural. Tyler Johnston, who plays Randy Klein in this episode, played Samandriel in three episodes of Supernatural. He also played Matt Pike in one episode of Supernatural. Julia Maxwell, who plays
Mary Pierson in this episode, played Eve in three episodes of Supernatural.
Chloe states that she has profiled 327 meteor freaks since ninth grade.
This episode marks the first time an episode has no scenes set in the town of Smallville.