'Stranger Things' star Sadie Sink said she started 'laughing uncontrollably' after seeing Vecna on set for the first time

• Sadie Sink said she laughed the first time she saw Vecna on the "Stranger Things" set.
• The villain's look was achieved with prosthetics on actor Jamie Campbell Bower rather than CGI.

Sadie Sink said that the first time she saw Jamie Campbell Bower in costume as Vecna while filming "Stranger Things" season 4, she burst out in laughter.

Sink has played Max Mayfield on Netflix's hit supernatural drama "Stranger Things" since its second season, which premiered in 2017. The final two episodes of the fourth season of "Stranger Things" were released on July 1.

While Sink had met the actor who plays Vecna, Jamie Campbell Bower, at a table read prior to the pandemic, she had no idea what his villainous form was going to look like before seeing him on set to film a confrontation between their two characters.

"When I first saw him, I started laughing uncontrollably," Sink told Vulture. "Just total laughter. I didn't know what I was looking at, you know? I was scared, but fascinated, and feeling such a weird array of emotions that it just came out as laughter."

Vecna's appearance fits right in with the slimy, vine-based aesthetic of the Upside Down, a parallel dimension from which the series' monstrous antagonists are based. His look, however, wasn't achieved through CGI but with prosthetics that Bower wore, Insider previously reported.

The official "Stranger Things" Instagram account posted a featurette showing Bower getting into costume, a process that the actor told The Hollywood Reporter took more than seven hours.

Sink told Vulture that Bower was "so convincing and believable" as Vecna that she "forgot there was a human" underneath.

Furthermore, she wasn't the only actor to have a visceral reaction to Vecna on set. Bower told Variety that Millie Bobby Brown, who plays Eleven on the show, "burst into tears" the first time that she saw him on set.

"I was looking at Vecna and I remember meeting Jamie in person, out of his Vecna costume," Sink told Vulture. "I heard his voice before I saw his face. And I was like, 'Oh my god, is that Jamie? Is this a sick joke?' Then I realized that's what he looked like underneath all of that."

"Stranger Things" season four is streaming on Netflix.