Watch 'Stranger Things' star Jamie Campbell Bower transform into Vecna with full-body prosthetics

Netflix's hit sci-fi series "Stranger Things" returned last month and introduced a terrifying new villain known as Vecna. But fans might not realize that this spooky character wasn't created with CGI — it's actually an elaborate set of prosthetics applied to actor Jamie Campbell Bower.

In a new video posted by the official "Stranger Things" Instagram account, you can see makeup department head Barrie Gower and his team working to apply head-to-toe prosthetics on the actor. In an interview with The Hollywood Reporter, Bower said the process took about seven and a half hours. Then an additional hour or so was needed at the end of the day to remove everything. 

You can watch the video in the Instagram post below:

Gower is a prosthetic makeup designer best known for massive projects like HBO's "Game of Thrones," for which Gower did all the practical effects for the Night King and White Walkers. His own Instagram account shows more behind-the-scenes photos of Bower getting ready to film scenes with Vecna and the rest of the cast. 

Bower is unrecognizable beneath the makeup that turns him into Vecna. Most "Stranger Things" fans were introduced to the actor in the flashback scenes between his "orderly" character and Eleven.

By the seventh episode of "Stranger Things" season four, "The Massacre at Hawkins Lab," we learn that Bower's character is actually Henry Creel — and the first child tattooed by Dr. Martin Brenner during the experiments inside the lab. That means Vecna is really Henry, who is really "001" (or just One). 

This massive reveal completely reorders our understanding of the "Stranger Things" timeline and story, showing that Eleven and Henry have been embroiled in a life-or-death battle for many years now. To learn more about why this reveal was so important, read our breakdown of the timeline here.

"Stranger Things" season four will conclude with a final two episodes that premieres on Friday, July 1. Read more about what to expect from the extra-long finale here.