Stranger Things season 2 showed us more of the nightmarish realm known as The Upside Down, including the introduction of massive creature that seemingly is the controller of that realm.
In keeping with the show's customs, the boys of Stranger Things define this new evil creature according to the terminology of their favorite game, Dungeons and Dragons. So what is the mysterious and terrible "Mind Flayer?" Here's what you need to know - along with some teases about the creature's future in Stranger Things 3, from show creators The Duffer Brothers:
The Duffers did an interview with THR, in which the facts about the Mind Flayer were laid out, with some intriguing teases for the already-confirmed, Stranger Things season 3.
First is the creature that inspired the name: in D&D, the Mind Flayer is a humanoid creature with an octopus-like tentacle face. It has psionic powers, which allows it to control the minds of others.
This is the analogy given to the creature from the Upside Down that is stalking and controlling Will Byers, as it has several tentacle-like legs, and is able to mentally control everything connected to it - including Will, the "Demodog" soldiers, and the entire alien vine system running under Hawkins.
The Mind Flayer is clearly able to control creatures across dimensional planes, and prefers environments with cold temperatures, according to Will. While it's plans are only vaguely defined as a hunger to conquer, it's clear that the Mind Flayer is set on transforming Hawkins into a realm like the Upside Down.
WARNING - This Section contains SPOILERS for the end of Stranger Things 2!
At the end of Stranger Things season 2, Eleven destroys the gateway between our world and the Upside Down, along with the lab where it was being studied. However, just because the one gateway is gone, it doesn't mean that Hawkins, Eleven, or Will and Co. are safe.
As the Duffer Brothers tease to THR, the Mind Flayer may now have a new target in mind (literally): Eleven. As the showrunners state, the Mind Flayer is now, "very much aware of the kids, and particularly Eleven. It had not encountered her and her powers until that final episode. Now, it knows that she's out there."
The rot underneath Hawkins is no longer a threat, as the Duffers confirmed in another interview, "That chapter of the storyline, in terms of the rift and Hawkins lab, that's closed."
However, there's no telling what threats are brewing on the other side of the gate, in the Upside Down, and just how vulnerable certain members of the town may be now. Hopper and Dustin were both exposed to the mucus being secreted by the dark vines running underneath the town, which (if what happened to Will is any indication) does not bode well for how they may be affected in season 3. But the biggest threat of all may be what we don't know yet:
The Mind Flayer is shown to be a central brain of a hive collective - but the Upside Down is a big place, and we have no idea if this particular Mind Flayer is but one of a larger species, or if there are different kinds of creatures still lurking in that dark dimension.