The Upside Down makes the danger in Stranger Things bigger than any single monster: an alien, hostile reality exists beside ordinary Hawkins, and humans can open a way into it without understanding what they’re letting through. That’s the Netflix series’ cosmic-horror engine. Creators the Duffer Brothers put an encounter with the unknowable inside a familiar suburban setting, where scientific curiosity can become a catastrophic mistake.
Stephen King and Steven Spielberg are often cited as the show’s main influences. But Nerdist’s reading argues that the series wouldn’t exist without cosmic-horror concepts developed by writers such as H.P. Lovecraft and Algernon Blackwood. Lovecraft’s At the Mountains of Madness is one reference point for that tradition: horror built around encounters with forces beyond human understanding, rather than simply an enemy someone can hunt down.
The clearest connection is the Upside Down itself. Lovecraft’s stories, particularly those associated with the Cthulhu Mythos, describe other dimensions where dark forces await. Nerdist’s analysis names the Dreamlands, the Outer Voids, and the Ultimate Gate as examples. They offer a useful comparison for the show’s neighboring reality, though a resemblance isn’t the same as a documented, one-to-one design source.
Even the vocabulary fits. The term “gate” is often used to describe portals and entryways into the Upside Down, which feels Lovecraft-inspired. More revealing is the parallel with From Beyond, in which a scientist uses a device on someone that opens their mind to other realities. The comparison with Dr. Brenner and Eleven is hard to miss. Humans meddling with things they don’t understand, then opening access to them, is a cosmic-horror staple the Duffers draw on heavily.
The Mind Flayer gives that hidden reality an apparently supreme presence. Particularly during the first three seasons, before Vecna, it invites comparison with Cthulhu: both are gigantic, monstrous figures that seemingly reign supreme in their own dark dimensions. The terror depends partly on not knowing enough to explain them.
Creator Matt Duffer described that intention directly: “There’s an H.P. Lovecraft sort of approach: this interdimensional being that is sort of beyond human comprehension. We purposely don’t want to go too much into what it is or what it wants.”
That restraint matters. In those early seasons, the Mind Flayer has more in common with the enormous, unknowable Cthulhu than with a villain whose motives can be neatly explained. Like the entities it resembles, it’s often contained but rarely fully defeated. Closing off a threat isn’t quite the same as eliminating it.
Nerdist describes the later revelation that the Mind Flayer was a creation of Vecna, who began life as a human on Earth, as a departure from that cosmic-horror tradition. In this reading, giving the antagonist a human origin makes it more knowable. There’s a genuine tension here: explaining the threat supplies answers, but it also reduces the mystery that made the earlier version frightening.
The name “Mind Flayer” comes from Dungeons & Dragons, as do many references throughout Stranger Things. Its name and its horror ancestry aren’t the same thing, though. Nerdist locates the creature’s deeper roots in Lovecraftian cosmic horror.
The series also gives the unknowable a biological form. Bio-organic monsters are another recurring feature of cosmic horror, with The Thing and Alien offering familiar screen examples. When Stranger Things introduces the Demogorgon in season one, it draws on that tradition of bodies that often look like a perversion of human or animal biology. Both the Demogorgons and the demodogs fit that mold. The threat isn’t only somewhere else; it can cross over in a living, physical shape.
Nerdist describes Stranger Things as one of the past decade’s most popular horror, or horror-adjacent, properties, saying that it brought cosmic-horror elements into the mainstream in a way nothing really had before. Bird Box offers another example of the genre reaching a broad audience, but cosmic horror might never be as popular with the masses as slashers, ghosts, or demons.
The source doubts the genre will reach that mainstream scale again, though it welcomes the possibility of being proved wrong and assesses that cosmic horror still has a lot of untapped potential for film and television.
