It’s been months since the premiere of reverent horror-drama Stranger Things on Netflix, but that hasn’t stopped fans from buzzing about the sci-fi series. From its adorable cast to its 80s aesthetic-generated cult appeal, many cannot wait for the series to return next year. Fans are eager to tie up many of the series’ loose threads, including getting more information on the show’s mysterious alternate world, the Upside Down.

The Upside Down’s most sinister inhabitant is the Demogorgon, so named by the show’s D&D-loving protagonists. A fearsome chimera, the beast preys on the hapless humans that fall into its world and acts as one of the chief antagonists of the show. An equally fascinating and disgusting creature, the Demogorgon has become notorious among followers of the show, with many eager to see if the monster will reappear in season 2. What fans may not consider, however, is how exactly the Demogorgon came to be.

While some images of the monster are engineered with CGI, a behind-the-scenes look at its creation reveals that the Demogorgon also has a version based in heavy prosthetics and practical effects. The company Spectral Motion, who have also worked on BirdmanPacific Rim, and the Hellboy franchise, took to Facebook today to shed some light on the iconic monster. Check out a video of their Demogorgon animatronics test, followed by a photo album dedicated to its SFX makeup process, below:

Spectral Motion, owned and operated by prosthetic makeup designer Mike Elizalde, reveal an extensive process behind the Demogorgon in these two posts. Many will likely be surprised to learn that the beast, at its most basic level, is actually a man in a suit, rather than a wholly CGI-constructed being. It appears as though the head piece we see at work in the video was then worn by actor Mark Steger (I Am LegendThe Pact), thus constructing the Demogorgon as a monstrous biped.

In a world of hyper-glossy computer effects, it’s great to get a look at some really well-done practical effects, even if they were mainly used as foundational material. Major props to actor Mark Steger for his work here, as well, since he had to perform some impressive stunt work in what was essentially a sensory deprivation suit — and all while on stilts and sporting inhuman appendages. Steger has the requisite resume for such a role, though, as he’s been creeping across the big screen in various monster roles since he starred as “Quadraped Alien” in Men in Black II. In an interview with Bloody Disgusting, Steger says that playing the Demogorgon “helped [him] remember why [he] loved film.”

Special effects artists really are the unsung heroes behind productions like Stranger Things, so it’s fantastic to finally learn about some of the people responsible for the beloved show’s thrills and chills. With such a talented cast and crew, it’s no wonder so many of us can hardly wait for season 2.

Stranger Things season 2 will arrive on Netflix in 2017.

Source: Spectral Motion