Case 03, File 16: Apocrypha

AKA: Aliens Drink Your Milkshake

Back when you first start watching The X-Files, you are always under the impression that the show has a long term plan for its Myth Arc that will eventually bear out. Once you've finished it, you realize that it was mostly just making it up as it goes, which is good preparation for disappointment from stuff like Battlestar Galactica or Lost. That isn't necessarily a bad thing; Junji Ito's Uzumaki was written by the seat of its pants and it has a great story and ending. It does make some individual episodes kind of messy though.

Case 03, File 15: Piper Maru

AKA: Oil Is Usually Black, Right?

Ah, the Black Oil. One of the most key components of The X-Files' internal mythology, and yet it didn't show up until over halfway through the third season. It's definitely one of the most memorable aspects of the mythology, visually distinct and utterly unique from most of the previously established alien mythology (which, aside from the Alien Bounty Hunter, have been pretty straightforwardly pulled from general UFO ephemera). And its introduction would mark a major turning point in the story.

Case 03, File 14: Grotesque

AKA: Gargoyles Are My Design

A lot of great horror is found in subtly, ambiguity, the sense of not being sure what's going on, which is why it's a bit of a shame The X-Files doesn't indulge in it very often. The Shining is one of the greatest horror films ever made, and that final shot, which makes you question everything that came before, is one of the big reasons why. Although, I will say, the usual lack of any ambiguity makes those moments where it pops up very memorable.