Photo Credit: Netflix, Marvel Studios
Marvel fans think they’ve finally figured out who Sadie Sink is playing in Spider-Man 4.

Marvel Studios and Sony Pictures’ Spider-Man 4, also known as Spider-Man: Brand New Day, arrives next summer. Directed by Shang-Chi and the Legend of the Ten Rings’ Destin Daniel Cretton, the film will once again see Tom Holland reprise his role as Peter Parker/Spider-Man.

Stranger Things’ Sadie Sink has been cast in an undisclosed role in the movie, though there have been plenty of online rumors and theories that have emerged regarding who she might be playing. These theories range anywhere from Gwen Stacy and Firestar to Jean Grey or Mayday Parker. It has also been announced that Sink will reprise her mystery role in Avengers: Secret Wars, which arrives in 2027.

What is the new Spider-Man 4 Sadie Sink casting rumor?

Speaking with Entertainment Weekly, Sink recently said about her Spider-Man 4 role, “A lot of people forget that hair color can change, but, yeah, I understand all of the theories…People will just have to wait and see. I’m excited for all of it to maybe be put to rest.”

In response to this comment, scooper Alex Perez of The Cosmic Circus said on Twitter, “I agree. Black works well on her. Also blonde. But then again…shapeshifter so.”

Given the “shapeshifter” comment, many MCU fans are now convinced that Sink will be playing Shathra in Spider-Man: Brand New Day and Avengers: Secret Wars. Created by John Romita Jr. and J. Michael Straczynski, Shathra is a wasp-looking villain who is able to shapeshift, among other abilities. Shathra first appeared in 2002’s Amazing Spider-Man #46.

Another common theory that has come up regarding Sink and the MCU is Chameleon, who is also a shapeshifter. Fred Hechinger recently played Chameleon in 2024’s Kraven the Hunter; however, Spider-Man 4 is set in a different reality than Sony’s Spider-Man Universe, so it could be a possibility.

Spider-Man: Brand New Day will be released on July 31, 2026.