Watching Stranger Things you probably see this question and go “well obviously it’s just Dungeons & Dragons.” Which is true, but unless you play the tabletop game names like “the Demogorgon” don’t mean much outside the context of the show. Or you’re up to date on your ancient deities. But if you’ve gone this far, you’re probably looking for more to “what are the Stranger Things monsters from?” than “oh uh Dungeons & Dragons.” Especially because they openly acknowledge that in the show already.
The Demogorgon’s origins don’t actually start with Dungeons & Dragons. It’s historically associated with Greek mythology, appearing for the first time in commentary on Thebaid. The Thebaid (The Song of Thebes) is an old epic by Statius dating back to around the 90s–90 AD not the 1990s.
Even the name “Demogorgon” is contentious; it’s normally ascribed to a misreading of the Greek word for “demiurge.” In Greek (dēmiurgós), the word loosely translates to “artisan” or “craftsman,” and later came to mean “creator.” The term “demiurge” was later adopted by the Gnostics as an entity responsible for maintaining the physical universe. They drew a distinction between a demiurge and a creator, as both the demiurge and universe exist as a consequence of something else. In many Gnostic systems, the material plane is perceived as evil, and the demiurge is therefore a malevolent entity. Somewhere along the line, Christians picked up and wrote the Demogorgon as a powerful figure in their demonology.
But you came here for Dungeons & Dragons, since that’s where Stranger Things picked up the name. The kids in the show dub the first season’s monster the Demogorgon because of their own tabletop game. But unlike the show, Demogorgon is a proper noun. In Dungeons & Dragons, Demogorgon is also known as the Prince of Demons. It’s a self-proclaimed title in the game’s lore, which means Demogorgon basically decided to call himself the Prince of Demons one day and nobody was strong enough to take it from him.
Which is just Pam calling herself the office administrator.
Demogorgon doesn’t look like a faceless-flower-headed monster either. He’s described as an 18 foot tall figure with two baboon heads, tentacled arms, and reptilian legs. Each head came with its own personality. The left is named Aeumal and is far more thoughtful than the more impulsive right head, Hethradiah. Neither head really likes the other all that much. Or at all.
The Mind Flayer
Luckily for this one we don’t have to do a history lesson. The long short of where mind flayers in Dungeons & Dragons come from is “heavily inspired by H.P. Lovecraft.” The one in Stranger Things is also heavily inspired by Lovecraftian horror, so they have that in common.
Mind flayers in the tabletop are humanoids with squid-like heads, and first appeared in 1975. They appear in a lot of Dungeons & Dragons-inspired media, like Final Fantasy.
Anyway, unlike Stranger Things, mind flayers aren’t giant incomprehensible spider-monsters. They’re more like a little cult that feeds on brains. “Mind flayer,” is also a nickname for “illithid” in Dungeons & Dragons, but we’re going to stick to the nickname.
In the tabletop’s fluff, mind flayers are said to have come from the future. Their species was on the verge of extinction and went back in time to preserve themselves. Speaking of species preservation, the way mind flayers go about that is straight body horror. They put a little tadpole in your eyeball that eats your brain and turns you into another mind flayer. Shoutout to the brain-eating amoeba?
Mind flayers are part of a hive mind, controlled by an elder brain. Which is literally just a giant brain sitting in a pool. Gross.
Vecna is the only straight “character” Stranger Things lifted from Dungeons & Dragons, though really it’s in name only. He also actually has a backstory, he was a king who wanted to become a god. He did that by becoming a lich, which is a very involved process by which a wizard becomes an immortal (ish) undead dude.
So death for the Dungeons & Dragons character is pretty meaningless, and in the fluff he’s already died twice and traveled through time at least once. The character has evolved a lot over time (he’s mentioned in every edition of the game), but he’s consistently one of the “big bads” in the Dungeons & Dragons pantheon. The guy loves secrets, but apparently couldn’t figure out the secret that his right-hand-man would betray him. After that betrayal, Vecna lost his left hand and one of his eyes.
The Eye and Hand of Vecna are iconic artifacts that really just screw with tabletop players–they’re the only parts of his original body left and if you want to use them you have to self-amputate. They also predate most of Vecna’s backstory, the Eye and Hand would appear in the original 1976 ruleset of the game. More of the character wouldn’t be built until 1989. It’s something Stranger Things pays homage to, considering the guy also has a janky left arm.
Honestly if you’re clicking on this post you probably know who is and isn’t in the show. You can make sure here, though.