The X-Files was groundbreaking television. Many of the show’s standalone episodes rank among the best television of the '90s. Fox was an upstart TV network at that point and willing to stretch the boundaries of what was acceptable prime time content.
The result was a number of overtly disturbing episodes that retain their eerie power, even after nearly three decades of increasingly intense network offerings. Most of them occurred early in the series’ run when the writers were fresh, and the creative concepts felt new. But they helped The X-Files overcome its late-season doldrums, and today they still stand out as some of the most disturbing moments in network series history.
Season 1, Episode 3 – Squeeze
“Squeeze” arrived early in the series’ run and immediately signaled that The X-Files was willing to go to some truly scary places. The episode’s boogeyman, Eugene Tooms, became one of the series' signature monsters: a seemingly normal man who devoured human livers to survive and regenerated his body by hibernating for 30 years. He stretched his body to slide into impossibly small ducts and openings, allowing him to slip into locked buildings with ease.
The combination proved deeply unsettling, so much so that the showrunners brought the character back for a second episode. His surface normality added the final touch: a literal human monster walking unseen among the populace, who had the power to ignore any door or security system. Add to that his baffling modus operandi -- which didn’t follow any well-known rules the way more familiar monsters did -- and the inferred grotesqueries of his hibernating nest, and the series set an early high-water mark that it struggled to top.
Season 1, Episode 11 – Eve
Small children can be inherently creepy, as can identical twins. The X-Files parlayed that into a second early high point with “Eve,” a retake on The Boys from Brazil involving sociopathic clones. The episode adeptly misdirected the audience to a series of murders' source, suggesting everything from aliens to vampires before finally deducing the actions of clones. Mulder and Scully assembled the pieces slowly enough to drive the tension high. The girls played victim early on and were even abducted at some point. It put their behavior in chilling context when the depth of their homicidal lies was revealed, turning what appeared to be passive trauma into icy, murderous patience.
Season 1, Episode 21 – Tooms
Eugene Tooms was too good to stay away from. While most of the show's "Monsters of the Week" never re-appeared, he did so before the inaugural season concluded. Incarcerated after his first appearance, Tooms released from custody, with only one liver left to claim before engaging in his hibernation cycle and escaping the FBI. This time, Mulder was the focus of his attention: the monster’s curtain call found unsettling new ways to toy with his creepy abilities, including the ominous suggestion that he could reach up from a toilet's flush pipe, and the sight of Tooms finally ensconced in his bile-laden nest. Its ending caused every viewer to think twice the next time they stepped on an escalator.
Season 2, Episode 2 – The Host
CGI was blossoming when The X-Files ran, but practical effects tended to produce the most lingering impressions. “The Host” enjoyed the full benefits of that: a monster born out of Chernobyl and so disturbingly convincing that it elicited shudders from the moment it appeared. The episode opened with a Russian sailor being messily pulled into his ship’s septic system and included the monster’s ability to inject flukeworms into its victim when it feeds. When added with the creature’s strangely believable appearance, it triggered viewers' fears of parasitic infection and unsanitary conditions, as well as simply being terrifying in its own right. Along with Tooms, it became one of the signature monsters of the series.
Season 4, Episode 2 – Home
Throughout The X-Files’ long and successful run, only one episode opened with a Viewer Discretion warning. “Home” aired only once on Fox’s network line-up before the episode was pulled from circulation and stayed off the air for years before finally cropping up on Fox’s F/X cable station. It remains infamous to this day: a riff on “corrupted family” horror in the vein of The Hills Have Eyes and The Texas Chain Saw Massacre. Themes of incest and taboo couplings combined with images of deformed infants buried alive, deputies torn apart by homestead booby traps and the incestuous clan’s limbless mother kept underneath a bed were horrifying enough on their own. But “Home” never added aliens or similar fictional material. Its monsters were fully human and could conceivably exist, which only enhanced its already gruesome content.
Season 4, Episode 6 – Sanguinarium
The X-Files never shied away from body horror, and “Sanguinarium” delivered an entire episode full of it, featuring a plastic surgery wing beset with what appear to be acts of witchcraft. The occult trappings added spooky flavor, but the episode really based its scares on gore, including liposuction gone wrong and surgical tools teleporting inside someone's intestines. The topper was the sight of a villain slicing his own face off, one of the straight-up bloodiest moments in the show’s history. The episode was criticized at the time for leaning on the bloodletting at the expense of the script, but it ensured that at least the first half of that equation was memorable.
Season 6, Episode 7 – Terms Of Endearment
Bruce Campbell guest-starred in a retake on Rosemary’s Baby, with an apparent demon trying to conceive a child with a human. The notion of Satanic infants was a little cliché at the time of airing, which the episode overcame with pure shocks. It began with disturbing ultrasounds depicting a baby with apparent horns growing out of its head. From there it moved into a full panoply of pregnancy horror, with fetal mutilation, abortion and scenes of a demon ripping an unborn child out of its mother’s womb. The excess was a nod to Campbell’s Evil Dead films, and the episode placed its tongue similarly in its cheek, but the onscreen grotesqueries produced a lot of sleepless nights among The X-Files faithful.
Taken from: Comic Book Recourses