The musical cue that plays when Gail places the rat trap in the closet is used in the movie Night Of The Living Dead. It is from when Ben kills a zombie with the rifle for the first time. There are two other links to Night Of The Living Dead via its remake. Tom Savini, episode director, also directed the remake of the original film. Patricia Tallman, who performed stunts in this episode, was one of the remake's stars.
The closet monster was named "Lizzie" by Tom Savini, and there was an actual Lizzie monster doll on sale on Ebay a few years ago.
Fritz Weaver, who plays Dr. Fenner in the episode, also starred in an episode from the motion picture Creepshow, which the Tales From The Darkside series was based on. The episode, entitled "The Crate", concerns two college professors who discover a monstrous creature housed in a large crate underneath the campus basement staircase. Coincidently, Tales... utilizes much of the same music employed in Creepshow. Fritz would go on to star in a second Tales... episode entitled "Comet Watch" and is also an alumni of two Twilight Zone episodes, "Third From The Sun" and "The Obsolete Man".