The massive cast of “Avengers: Doomsday” continues to grow, with one of Marvel’s tiniest stars officially joining the project.
On Friday, April 17, Kathryn Newton, who starred as Cassie Lang in “Ant-Man and the Wasp: Quantumania” confirmed she will team up with the Fantastic Four, Thor, Captain America, Black Panther, the X-Men, and the New Avengers to take on Robert Downey Jr.’s Doctor Doom.
The reveal comes after a brand new trailer for the superhero flick was shown at CinemaCon in Las Vegas on April 16.
Kathryn Newton Confirms Her Marvel Return
Taking to her Instagram page on April 17, Newton shared a video showing her opening up a mystery package.
“It must be important, but I’m working, and it’s very rare I get a package. I think it might be something special,” she teased.
Indeed, it was special, as Newton eventually revealed a mini director’s chair with her name and “Avengers: Doomsday” written on it. The Russo Brothers and Marvel, of course, initially revealed some of the film’s stars with a live YouTube video in which the cast names were shown on director’s chairs.
“And it’s tiny because Cassie Lang gets tiny. She’s small,” Newton said of her chair, as Cassie—like her dad Ant-Man—can change her size. “Sometimes she’s big, it depends. It depends on what’s happening.”
Newton then donned a Doctor Doom-green hat with the movie’s logo on it, before telling fans she was “grateful” and would be seeing them “in cinemas” soon.
Doomsday Trailer Shown at CinemaCon
While a few teasers for the film were shown before “Avatar: Fire and Ash” back in December 2025, the first real trailer was shown to press and exhibitors at CinemaCon in Las Vegas on April 16. The footage hasn’t officially made its way online yet.
At the panel, Marvel’s Kevin Feige, per The Hollywood Reporter, said the movie “picks up where ‘Avengers: Endgame’ left off” and will show the Avengers meeting the X-Men for the first time.
According to the outlet, the trailer showed Robert Downey Jr. putting on the Doctor Doom mask, Chris Hemsworth’s Thor saying they’ll need a “miracle” to defeat him, and the return of Chris Evans as Captain America, once again proving he’s worthy enough to wield Thor’s hammer.
Gizmodo also reports the footage showed Rebecca Romijn’s Mystique facing off against Florence Pugh’s Yelena Belova, with the shapeshifter turning into Yelena as they fight. Cassie also appears in the video, as do Namor, Sue Storm, Shang-Chi, Cyclops, Professor X, Shuri as Black Panther, the Thunderbolts and Gambit.
The movie is set for a December 18 release.
