Spoiler Alert: Do not read if you haven’t watched the Volume 1 finale of “Stranger Things 4, now streaming on Netflix.

Season 4 of “Stranger Things” introduces a new big baddie to the hit Netflix series in the form of Vecna (Jamie Campbell Bower), a menacing “dark wizard” that stalks the teens of Hawkins, Ind. According to Barrie Gower, the prosthetics designer behind the character, he was approached by the Duffers with the request that he design them an iconic villain for the world of the show.

To create the character, Gower was given concept art from series designer Michael Maher, but precious little information about the creature he would be designing.

“They have this artwork, which is beautiful, and we had the name of the character, but we didn’t have any backstory at all. We knew it was from the Upside Down, but we had no idea if this character was once human and we had no idea the whole story arc would be told throughout this season.” Gower told Variety. “From a makeup effects team point of view, none of us were privy to Jamie’s role as the orderly, and all of the scenes he show with Eleven [Millie Bobby Brown]. So know actually seeing it for the first time, we’re in awe of this whole story arc.”

Gower and Bower joined Variety senior artisans editor Jazz Tangcay for an installment of Variety Artisans presented by HBO. The two discussed the process of creating the main villain for “Stranger Things” fourth season, which premiered May 27 and is set to release its explosive finale July 1.

According to Gower, the Duffer Brothers were very intent on having the character be done mostly practically, as a way of creating a real physical presence on set. To transform Bower, Gower said the team essentially applied an entire “second skin” Bower, with around 25 pieces of latex or silicone rubber material being glued to his body via a medical adhesive.

By the end, the entire suit weighed roughly 30 pounds when applied to Bower, with the most weight coming from the chest and head pieces. Although Gower said that Bower “deserved a medal” for putting up with the amount of prosthetics and the time it took to apply it each day, Bower said that it was something he eventually got used to, and he eventually made a routine of putting on music during the appliance period to help him get into the zone of Vecna.

“Often I’d finish the day, and the next day I’d be so tired and hungry that I would just eat everything I could see in site. So being able to work out with that on was probably a benefit,” Bower said. “You just get used to it. We’d done the test in London, so from that point in I knew what the process was going to be like. So I was like, ‘Cool, I now know this. I’m set, I’m ready to go. I know what I can do to help myself get into the space I need to be in.'”

“Stranger Things 4” is streaming on Netflix. Watch the full Variety Artisans video above.