AceShowbiz - Jamie Campbell-Bower's "Stranger Things" elaborate costume was equipped with a special "undercarriage" popper so he could comfortably take bathroom breaks.
The 33-year-old actor plays Henry Creel/Vecna, the murderous being in the Upside Down in Season 4 of the Netflix sci-fi series, which also stars Winona Ryder, David Harbour, Millie Bobby Brown, Joe Keery, and Finn Wolfhard.
Jamie's monster prosthetics took several hours to apply and so Barrie Gower - the head of BGFX, the special effects house that collaborated with the show's creators, The Duffer Brothers - designed an easy access point so the actor could relieve himself with ease.
Speaking to SFX magazine, Barrie said, "With his trousers he had an undercarriage which we could un-popper and release him so he could go to the loo. He could unzip and take his shoes off, he could take his left hand off. We didn't cover his armpits. "There were certain areas on the left arm which we didn't overlap completely with all the appliances. There are patches on his body which rubber doesn't overlap and cover, so there's areas for his skin to breathe."
Barrie - whose work on "Chernobyl" and "Game of Thrones" was what caught the attention of Matt and Ross Duffer - shared how Jamie "was very surprised" to see that his acting could shine through his "very thick second skin" of prosthetics.
He said, "I think he was very surprised that a lot of what he was doing underneath was translating through the prosthetics as well. When he breathes, you can see his chest increasing and deflating. A lot of his facial movements were coming through the pieces as well."
"With any prosthetics, when you're giving somebody quite a thick second skin, actors have to almost over-exaggerate everything as well for things to read through. So it was a good process for him, just to get used to the weight and the feel of everything prior to doing the final camera test. But his response was super positive."
Barrie recalled how Sadie Sink - who plays Maxine "Max" Mayfield who is targeted by Vecna - "was terrified" when she first acted opposite Jamie in his Vecna costume in the episode "Chapter Four: Dear Billy".
He said, "When Sadie Sink first met Jamie in the Vecna makeup for episode four, her reaction was fantastic. It was brilliant - she was terrified, which is exactly what we wanted."