25 best standalone episodes of The X-Files

10. “The Host”

If Eugene Tooms was an impressive monster of the week, then you should really keep an eye out for Flukeman. No, seriously. Maybe go check your local wastewater processing plant, just to be certain. I’m sure the workers will understand.

Like Eugene Tooms, the creature from “The Host” is creepy as all get out. It’s also pretty dangerous to humans, though more because of its general hunger and desire to parasitically reproduce rather than wanting to consume livers.

The first sign of Flukeman shows itself on a Russian freighter just off the New Jersey coast. A crewmember is pulled into the ship’s sewer system; his mangled corpse shows up in the sewers of Newark, New Jersey days later.

Scully performs an autopsy on the unidentified body, discovering a Russian tattoo and, more frighteningly, a live flukeworm. Meanwhile, a sewer worker named Craig is pulled into the sewer system beneath Newark by a mysterious force, though a co worker saves him.

However, he soon begins to complain of an odd taste in his mouth and shows his doctor a strange wound on his back. Though Mulder and Scully believe that the wound corresponds to the strange flukeworm found in the Russian body, they can find nothing more wrong with Craig. Of course, the effects of his implied encounter with Flukeman are far from over.

In fact, Mulder and Scully eventually capture the Flukeman with the help of some workers at a wastewater processing plant. They get a good, close-up look of the creature, which shows itself to be a deeply upsetting blend between a flukeworm and a humanoid creature. However, Flukeman soon escapes their grasp. The investigative duo from the FBI have their work cut out for them.

By the way, Flukeman is played by Darin Morgan, brother of executive producer Glen Morgan. Darin would go on to become a staff writer for the series, producing some of the most critically-acclaimed scripts of The X-Files.