This episode was a deliberate attempt by producer Chris Carter to prove that the show could be about more than just aliens.
In "Squeeze" and Tooms (1994) two actors played the character of Eugene Victor Tooms: one who appeared as the main character, the other a contortionist who was responsible for squeezing into the tight areas that Tooms was able to do.
This episode contains the very famous shot of Mulder and Scully in the credits that we would see along the years. We can see it when they enter in Tooms lair.
Doug Hutchison is one of two actors who played the character of Tooms, a liver-eating mutant, in "Squeeze" and Tooms (1994). Hutchinson is actually a vegetarian, or was at the time. After filming "Tooms" he sent the liver of an animal to Chris Carter as a thank you for the opportunity to play a character on "The X-Files".
Previously, the story was related to the aliens or the conspiracy. This is the first typical Monster of the Week that would be the other classic kind of story in The X-Files. Besides, it has one of the most legendary Monster of the Week that would be remembered along the entire series.