How Billy Hargrove Got His "Flayed" Look For Stranger Things Season 3

When Billy Hargrove (Dacre Montgomery) rolled up to Hawkins, IN, at the start of season 2, he instantly became the most hated (human) character in the Stranger Things universe. But during season 3, Billy became something else entirely: the Mind Flayer's newest victim, replacing Will Byers (Noah Schnapp) as the unfortunate host to an interdimensional monster.

Just like Will in season 2, Billy's physical appearance drastically changes after his body is invaded by the Mind Flayer, a shadow creature from the Upside Down. Overnight, Billy goes from tan and toned to pale and haggard. The lean, literally mean lifeguard the mothers of Hawkins once ogled at spends the rest of the season covered in sweat, blood, and a stomach-churning goo courtesy of a soul-sucking monster.

To get the lowdown on how Montgomery transformed into Stranger Things' seriously flayed antagonist, we went straight to the source: Amy L. Forsythe, the show's makeup designer. Ahead, Forsythe tells us every behind-the-scenes secret you need to know — and trust, once those credits roll, you will be looking for answers.

Billy Gets A Badass Tattoo
"Dacre really wanted Billy to have a tattoo in season 2, but his character was still in school and we weren't sure that was appropriate yet. This year, I didn't see a problem with it, and [directors and co-creators Matt and Ross Duffer] agreed.

"I work really closely with Jeremy Sutton, a tattoo artist and owner of Electric Anvil Tattoo in New York, and he designs a lot of tattoos for me. I sent him a bunch of images of skulls smoking and he created something custom for Dacre. We did play around with the idea of giving the skull an eyepatch as a nod to The Goonies, but it was just too much. I wanted to keep it minimal."

Billy's Eyebrow Scar Has Its Own Backstory
"Dacre is a pretty guy, so we kind of have to mess up his face a little bit and make him a little more rugged to become Billy. We gave him a scar this year. Dacre really wanted it, but I kept it subtle — it isn't unrealistic, since Billy probably got into a fight since the last time we saw him. We also have to bleach his facial hair, shave it down, and patch it up to make it look a little more prepubescent."

Billy's Sunburn You Didn't See
"When Billy is normal and healthy, he's tan; when he's flayed, he's supposed to be pale. Then, one time when we were filming a pool scene, Dacre was in the lifeguard stand sitting directly in the sun for the entire shot. He ended up getting sunburnt on his back. Then, we had to film the shower scenes where Billy slams up against the wall and tumbles down to the ground. Dacre kept slamming against the tattoo cover-up we used to cover up the burn and scraping it off. We'd have to go in and redo it for every take."

Self-Tanner Saved The Day
"Dacre's skin is naturally tanned. He's from Perth, Australia, and he loves being in the sun. If he had any tan lines when he took his shirt off, like a tank line, I used Vita Liberata's tanning mousse to even it out and Prtty Peaushun lotion on top."

Billy's Sweat Came Courtesy Of MAC
"MAC gave me some clear Lipglass, which is a really viscous lip gloss, to use as a slimy sweat on the flayed characters. I'd have a base layer of sweat on Dacre, then I'd add the mud that I created for Hopper in season 2, and then I'd top that off with the Lipglass, adding just a little bit of a tint to the formula to create a gooey consistency on top of everything.

"Making Billy a sweaty mess was fun. When he comes out of the basement and runs to the telephone booth, that confusion of still being the old Billy but becoming the new flayed Billy was beautiful. He still had the slime on him, the sweat, the mud, the tears — it was really cool. And we had that juxtaposition of seeing filthy Billy next to the clean, flayed Billy. There was something very eerie about it."

Dacre Wore 33 Prosthetic Wounds
"We ended up having to establish all of his wounds way earlier than anticipated because Millie [Bobby Brown] broke her knee while we were on our first hiatus. I got a call during the hiatus giving me a heads up about doing the post-sauna scene with Billy on the stairwell getting his wounds nursed the day after we were to get back from hiatus. I hadn't even seen a preview for the sauna fight, so I didn't know how he was getting hurt or where his wounds might be. I just had to have a bunch of stuff made and hope that it would work. I had 50 different kinds of prosthetic pieces made and we had to rush-order all of them from Robert Kurtzman MUFX, who made them for us very quickly.

"I had initially asked the Duffers if they wanted Billy to bleed red and heal like a human typically would. After we had established that he would, and shot the first scenes, they decided to change it to black. The initial prosthetic shots had to be changed in post-production, and we then had a second round of prosthetics made by Bill Johnson at Lone Wolf Effects. We were really figuring it out as we went because we wanted it to make sense. Dacre ended up wearing 33 prosthetics at a time. Between him and his photo and stunt doubles, we had 99 prosthetics on them in total."