I'm a big fan of The X-Files and have been since I was twelve or so. But there are some episodes that are just unwatchable, not just because they're terrible (but some are), but because they contain content that I just don't want to see. Not everything on this list qualifies in that category. A show with horror elements like this can be effective with a jarring image or two; some of my favorite episodes have something icky in them. But here's a list of what I think are some of the ickiest things the show ever did. You'll notice that there are more episodes from the later years; you can tell they kept trying to push the envelope with the gore. It's surprising actually the stuff they got away with on a TV-14 rating, while Fox was still running Scream edited with a TV-MA.
There's not a lot that's too gross in this episode, and I almost didn't include it. This was the first time we learned about stabbing Alien Bounty Hunters in the back of the neck, and saw what happens when a hybrid dies. They have toxic green blood that dissolves their bodies. We actually see this. The first time you see the dissolving head in bubbling green goo is a bit jarring, but it's a cool effect. Even that isn't what most disturbs me though. There's a scene where the Bounty Hunter destroys the cloning facility the hybrids were working in, and kills a growing alien hybrid fetus. It's in a bag, we see it wiggling, and then he stomps on it, as its green blood oozes out. What's most shocking about this is that it could be shown so vividly; this is essentially an on-screen abortion.
14. Bad Blood
This is a great episode. It's very funny, and it's fun to see how it toys with the Mulder/Scully relationship. For a story about vampires, it's also bloodless. But then there are those autopsy scenes which are some of the most graphic of any on the series. They are meant to be funny; the over-the-top look at the sort of things Scully REALLY does every time Mulder has her autopsy someone. But even given that tone, it's really gross and jarring the first time you see it, and takes me out of the episode for a second.
13. F. Emasculata
This is bound to be grosser to some than to others. The plot here involves bugs that infect people with these huge bulging pustules all over their skin. Throughout the episode, some of them burst, getting infectious pussy stuff on others, including our hero. Ticking time bombs are great for drama, but when they are made of bubbling flesh... ew.
Not terribly offensive, and a pretty good episode for season 9, but it also has the mother of projectile vomit scenes. Apparently, it wasn't shot to be this way, but when they cut it together they used every take from every angle, making it look like a geyser of gastric gunk.
11. The List
It's a guy on death row who comes back after execution to take revenge on those who wronged him. So people are killed off one by one, and their bodies are left covered with maggots. One of those bodies is the warden, who is decapitated. We first see his headless corpse, only to later discover the head in a can of paint.
It's an episode with problems anyway. This is an early television look at internet predators. Only this predator is a monster who has some sort of excretion that liquifies his victims. So we get the image when Scully opens the drawer at the morgue, and all that's left is a skeleton while all the soft tissue is now just a yellowish fluid that spills onto the floor.
9. Patient X
I know some people who were grossed out by the Black Oil when it was first seen floating across people's eyes. Or during the episodes in Russia when Mulder was infected with it, and we see it as little worms crawling under the skin. But Patient X takes all those elements one step further into the truly disturbing. Krycek essentially kidnaps and intentionally infects a Russian boy with the Black Oil, and then sews up his orifices so it can't escape. ...Then the kid eventually pulls the stitches out and it does escape. We also see the alien rebels for the first time, who have no faces because they've mutilated their own to not be infected.
This is just a bad episode. It's so poorly written. It's about a hack writer who goes around killing people and ripping their hearts out of their chests. It's supposed to be some kind of metaphor, but it's just stupid. So all we're left with is a wasted hour, and hearts in hand a la Temple of Doom. At least some fan with a sense of humor made the above music video out of it.
7. Brand X
A real case for not smoking, here we have cigarettes that infest you with tobacco beetles that clog your lungs until they eat you from the inside. The bit where the doctors are vacuuming beetles out of Mulder's chest is icky enough, but doesn't top the image in the teaser with that first corpse.
6. Via Negativa
Okay, I really like this episode. It's intense, but it's one of the best episodes without Mulder. But to get there, it goes further into slasher film territory. There's a dream image of Doggett holding Scully's severed head, and in another scene a guy slices his own face on a table saw.
5. The Host
One of the earliest of the show's bizarre and disgusting monsters is Flukeman, who is part man, part flukeworm. He's this icky thing with a giant circular sucker mouth and when he bites you, it leaves little baby worms inside you. The worst part for me is when the victim guy goes to brush his teeth...
There's just so much blood in this one and it's not even an interesting episode. It's about an evil plastic surgeon, so it ends up being all the ickiness of hospitals combined with extreme fantasy visuals. We see fatal liposuctions, people coughing up pins, a literal bloodbath, and a guy peeling his face off. This is one I just hate watching.
3. The Gift
I may have spoken too early regarding vomit. This charming story, and one of the few to feature Mulder in season 8, is about a town who has this being captive. When people are sick, this thing can absorb their sickness. The catch is, he has to EAT YOU ALIVE (feet first), then vomit you up into a giant person-shaped hole, and eventually you will resurrect out of that hole alive, but without whatever was wrong with you; that affliction becomes part of this guy. ...Who writes this stuff?? Also, it really strains credibility at this point in the show that Doggett could be eaten alive, barfed up and resurrected, and STILL be a skeptic to things paranormal. Scully was never THAT stubborn.
A little indian man with no legs crawls up inside morbidly obese people, and then explodes out of them. He actually travels by plane INSIDE somebody. Seriously? How can we even entertain the idea? And it's just disgusting. Besides which, the whole point was that the little man wanted revenge for something, but we never find out what, and in the end he's still alive and probably looking for another fatty.
This is the most R-rated I think they ever got. It's a story about a serial killer who skins people alive. We see his lair that looks like a butcher shop, only the hanging, dripping bodies are human. And in one of the most horrible scenes ever, we hear the screams as one guy is being flayed, blood dripping to the floor before it mercifully goes to commercial. To top it all off, the evil is never punished in this episode, so we spent an hour being tortured with no resolution. The episode has a bit of technical and dramatic merit unlike the one before, but it's still very hard to watch.
Well, that's my list. Are there any others that you would have put on your list? What gross-out did I leave off?