Love for Netflix’s Stranger Things has only grown in the weeks since its release, with more and more fans diving into the details and questions lurking in every frame. That word in particular perhaps best suits the so-called “Demogorgon,” a mysterious creature who calls to mind everything from Alien to Guillermo del Toro.

In order for Stranger Things to first envision the terrifying monster lurking within “Upside Down,” creators Matt and Ross Duffer first enlisted the artists at Aaron Sims Creative, visual talent behind everything from Disney’s Pete’s Dragon to the re-vamped look of The Amazing Spider-Man, who were given the task of designing a “humanoid creature with no face, just a mouth.”

We had a chance to speak with Sims and examine concept art spanning the whole of Upside Down, from the creature’s fullest appearances, to the surprisingly gruesome first pitch for poor Barb’s demise.

The Monster at the Beginning of This Book


Desperate to make sense of the blinking lights on the wall, Joyce Byers pleads with the disembodied presence of her son to spell out the help he needs. No sooner can she grasp the cryptic message from the lights claiming Will is “R-I-G-H-T-H-E-R-E,” do the ominous blinks add more terrifying urgency: “R-U-N.”

Suddenly the wall behind Joyce oozes to life, as the shadowy figure glimpsed about town finally bursts through the membrane, one bony appendage at a time. This is the Demogorgon, realized in its most terrifying clarity to date.

The creature itself remains in shadow through its first appearances, both for movie-magic’s sake of a true first reveal, as well an in-story source for descriptions of its humanoid, faceless form. Sims went through several early concepts for the Demogorgon, some more outwardly monstrous, but ultimately looked to nature for the terrifying and distinctive petaled-mouth:

One of the designs we came up with the first week was a flower petal-like face with no teeth. That really resonated with the Duffers; it answered a lot of questions the Duffers had about the uniqueness of a monster with no face, and how that could be terrifying. A lot of the inspiration also came from the mouth of a snapping turtle - how terrifying that looks, and how its teeth go all the way back. So there were always teeth in our design.

Some of the early concepts were more monstrous in shape, even more asymmetrical. Those were ones that veered off into their own direction, so we ended up scratching those and focusing on more symmetrical designs.

The Duffer brothers themselves previously listed among the creature’s inspirations Alien, H.R. Giger and Guillermo del Toro. Sims corroborated as much of early conversations with the directing duo, without intending to supplant the horror masters’ most recognizable imagery:

What really inspired us with Giger were the very iconic elements of his alien designs. Our goal was to reach something like this level of icon - it’s impossible to ever go beyond that, as Alien has one of the most iconic creatures to ever exist on film.

The fantastical elements of del Toro are always inspiring, and Clive Barker’s work has a hellish quality that we wanted to maintain. The directors are especially influenced by these three, especially the 80s feel of Giger’s work.

It took a mixture of CGI and practical effects to bring the Demogorgon to life, as Sims points out that his team (Joshua Min, Nattawut Baiphowongs, Steffen Reichstadt, Jared Krichevsky, Tsvetomir Georgiev, Daniel Edery and Mikhail Rakhmatullin) went through the process of reverse-engineering the way contortionist Mark Steger could wear it as a suit.

“The use of full CG was more related to when an actor in a suit couldn’t perform certain stunts - especially when we had supernatural elements, like the Demogorgon breaking through walls,” he adds. “We had to show another world reaching into ours, and those shots had to be fully VFX.”

According to Sims, very little of the creature’s design went through additional tweaks after formal approval from the Duffers, though “There was a point where the creature was shot and burned and beaten, so it needed a look that seemed like it had really gone through all that.”


That damage coincided with the creature’s final appearances in the high school, the bright lighting and action of which informed a decision to “make that mainly CG.”

Alas, Poor Barb


Dejected, and abandoned, Barb sits atop the diving board, dragging her feet across the surface of a well-lit pool. A trickle of blood from her bandaged thumb splashes into the water, as the lights suddenly flicker out. A towering figure meets her upward gaze with only an ominous gurgle, and lurches forth.
In the bushes nearby, Jonathan Byers glances up from his camera to find the scene deathly quiet.

Stranger Things mourned for Barb in the … well, strangest of ways, to pick up from that harrowing scene the very next episode with Barb’s gooey and extended torment at the bottom of the pool, now empty of all but the Demogorgon and its muck. It wouldn’t be until the show’s penultimate hour that Eleven finally confirmed Barb beyond rescue, leaving Shannon Purser’s delightfully ‘80s icon among the series’ only innocents to die.

Believe it or not, it was almost way worse.

Aaron Sims Company

Yeah, that worse. What real-world monsters would inflict such unyielding horrors on our future Squirrel Girl?

Based on our original discussion with the Duffers on this design, we wanted to go really graphic with it to highlight the horrific aspects of Barb being eaten, and something then growing on top of her - thus, the ribs poking out of her stomach in the first shot.

Well, at the very least, it couldn’t get any OH GOD IT’S WORSE

Aaron Sims Company

So, what then changed the Duffers’ minds? “In the final design, they ended up veering away from that because it became too unrecognizable,” said Sims. “It was difficult to tell exactly what had happened to her; it wasn’t an issue of it being too graphic, but rather, that the viewer needed to see something that was very recognizably dead.”

That’s all very well and … wait, are there spiders in Upside Down now? WE HAD JUST STARTED SLEEPING AGAIN, GUYS

In the script for that episode, there was specifically a description of a spider coming out of her mouth, which we incorporated into the design of that second shot … we don’t really have an explanation for its existence; the design is based around the script’s description.

If nothing else, confirmation of Barb’s gruesome end brought us closer to defining a biological impetus for the Demogorgon, to feast on its victims and store others in a mucus-y membrane, complete with slugs. Sims wouldn’t offer any insight into the slugs themselves, or the webbing that surrounds them, which “won’t be revealed until later seasons,” but solved the mystery behind at least one physiological oddity:

Aaron Sims Company

If the image above seems unfamiliar, there’s good reason for that. Little was made of the hollowed-out “egg” that Hopper seemed to find in the finale’s Upside Down search for Will, leading many to speculate the creature might somehow have reproduced in time for Season 2. As it turns out – we’ve actually seen that “egg” before without realizing:

The egg was a design for something you actually see a couple times in the show, whether you recognize it or not. There are a couple encounters where we see the Demogorgon hunkered over, eating something - when Nancy goes into the Upside-Down through the tree, and when Eleven finds the creature in her “vision”, it’s hunkered over this egg, feeding off of it.

It’s not clear whether or not this is the creature’s offspring - we don’t even know if it’s the same species. The only info we have is that the creature is feeding off this egg somehow.

Upside Down


“Everything that’s happened here, and everything that’s going to happen, we don’t talk about,” Hopper intoned to Joyce, as MPs escorted the pair to the lab. “You want Will back? This place had nothing to do with it. That’s the deal. Got it?”

Hopper set his gaze on a rack of protective suits in the locker room. “What is this?”

“Protection,” a scientist clarified. “The atmosphere is toxic.”

“But my son’s in there,” Joyce seemed to ask. Hopper answered for her.

“Put it on.”


This wouldn’t be the first trip Stranger Things has taken to the “Upside Down” world, as that honor belonged to poor Barb at the bottom of Steve’s family pool. We’d get another wooded glance when Nancy and Jonathan took to hunting for the Demogorgon themselves, as Nancy ventures through a very gooey portal at the base of a tree into the creature’s ash-laden world.

We only ever saw Upside Down in its darkened, dreary state, but earlier in the process, Sims actually considered shining a brighter light on the demon hellscape:

Aaron Sims Company

This image was an early exploration of the Upside-Down and the rift that Nancy enters, in a period where we were still deciding on how much color we would incorporate, if any. At the time, we didn’t necessarily know if day and night existed in the Upside-Down.

We actually considered the possibility of a time change when going between the two worlds - e.g. Nancy entering the rift when it was nighttime in our world, and coming out into the Upside-Down in the day. In the end, our designs for the Upside-Down went toward what you now see in the show.

Looking back, we did see the Demogorgon making a daylight appearance once, darting by Nancy as she returned to the pool the next day. Still, Sims notes the scene was a practical consideration, and not one that required any of his team’s artwork or input.

The Duffers themselves again pointed to the likes of Alien and even the video game Silent Hill as ultimate inspiration for their nightmare dimension, one which mirrors our own to the last detail.  For Sims, however, the real design source was slightly more obscure:

We did take some inspiration from Alien when taking a world that we thought of as familiar, and then placing a sort of membrane all over it. In the same way, when the Alien eggs would grow in certain areas, it would affect our world.

More specific influences came from the art of Polish painter Zdzislaw Beksinski, whose paintings felt slightly hellish. They reflect an otherworldly, hellish world, surrounded by a thin layer of something we can’t quite make out. They’re terrifying, and were definitely an inspiration for our work here.

Sims based most designs of Upside Down around “the exploration of terrifying images and art,” rather than attempt to mimic any scientific theory of alternate dimensions, though physical decay formed a tentpole of the finished look. “We took the idea of mold and things that have decayed. The film that grows on these things helps create an image of a world that is, in some ways, ‘dead’.”

Aaron Sims Company

Perhaps most memorable among Upside Down’s nightmarish imagery is that of the falling, ash-like substance that seemingly owes to similar phenomena in the above-mentioned Silent Hill. Sims thought mostly of the substance as visual shorthand to distinguish between the two worlds, but acknowledged at least some connection to the Demogorgon, which might inform future story:

We really used the particles in the air to represent the difference in the two worlds, rather than a specific relationship … There is some idea that if the creature existed in our world, the particles would exist here as well…but no word on the specific relationship.

Co-creator Matt Duffer had previously spoken to some uncertainty during the first pitch that they’d ever actually visit the otherworldly dimension, at least until ASC drafted a practical concept. And while Sims notes that the look of Upside Down had coalesced early on, the actual barriers between worlds vacillated from different concepts:

The only thing that really evolved was the opening in the lab - the rift to the Upside-Down. That portal was an explorational process that went through variations of looks and feels. Many of the early designs felt “too sci-fi”; we wanted it to feel grounded, somewhat disgusting, like looking at the inside of a body. As opposed to a portal to a parallel universe, this felt like a membrane, like a physical organ.

Aaron Sims Company

It stands to reason Season 2 would unlock additional secrets of either Upside Down, or the Demogorgon itself, though no design work has officially begun toward a prospective second season. Like us, Sims is anxiously awaiting that greenlight, but what other scary secrets of other dimensions do future Stranger Things hold?

(All images republished with permission. Special mention and thanks to ASC artists.)