One of the coolest things about Netflix’s Stranger Things was the show’s antagonist, a horrifying monster that the show’s characters took to calling the Demogorgon. As the show has been praised for emulating the works of Spielberg and Carpenter, the actor behind the character has his own inspirations for horrifying audiences.

Mark Steger originally became interested in performance through an experimental movement performance group he co-founded in 1989 called called Osseus Labyrint. He ended up moving to Los Angeles, where he put his skills to work in music videos such as Tool’s Schism, and eventually appeared in films such as I Am Legend and Men In Black II. He also worked as a choreographer for World War Z and American Horror Story.

His work with creatures, cinematography, and movement led him to appear in Stranger Things as the Demogorgon. The monster was first designed by the Aaron Sims company before the designs were handed off to Spectral Motion, a makeup and creature effects studio which has worked on productions such as Hellboy, Pan’s Labyrinth, and Pacific Rim. "It was a pretty quick development process, Steger noted, saying that it took the company about three months to design the costume.

They started off with a laser scan of Steger’s body, from which they made a full-sized form of his body, on which they began to sculpt the body of the monster. As the costume came together, he said that he began to work out how the monster would move while suited up. The company installed animatronics to control the complicated head and arms, which required a puppeteer with a remote control to operate. "It was the most complex creature suit I’ve worn." He told The Verge. "It was an amazing work of engineering."

It was also fairly easy to put on. Steger noted that the longest time that he had sat in a makeup chair was for the music video for Tool’s 2001 song Schism, which took almost 16 hours to apply. He ended up spending the next four days in costume during the shoot. By comparison, the monster for Stranger Things was incredibly straightforward, despite its complexity. Depending on the attachments, it only took about 30 minutes to suit up.

Like Jaws and the other shows that Stranger Things drew on, much of the work was done practically on set, rather than on a computer. The production emulated Spielberg’s classic film in other ways: the monster is rarely seen until the climax of the show.

To bring the creature to life, he called on his own past experience from other productions. The Duffer Brothers were particularly inspired by a number of other cinematic monsters, ranging from the alien from The Thing to the one in Alien. The creature that stuck out the most, Steger noted, was not from another world, but our own: the shark from Jaws. He likened the Demogorgon to "this entity that appears from time to time to feed," he told The Verge, "so I imagined myself as this [creature] that hasn’t evolved much over hundreds of millions of years because it’s so perfect at what it does."

Steger didn’t have much to say about any sort of return if the show gets picked up for a second season, but noted that he’d be back if asked. "I hope they do another season," he said, "I’d be happy and honored to do it again, because I had a great experience on the first one."