Avengers: Doomsday first trailer stuns CinemaCon — RDJ’s Doctor Doom battles Thor and the X-Men in epic MCU footage

Marvel Studios wowed CinemaCon audiences on April 16, 2026, in Las Vegas, revealing the first full theatrical trailer for Avengers: Doomsday, featuring Robert Downey Jr. as the armoured supervillain Doctor Doom battling Thor, the X-Men, and a surprise returning Avenger, ahead of the film’s December 18, 2026 release.

The trailer that broke CinemaCon

Until the CinemaCon presentation, Marvel had released only four brief teasers — focused on Steve Rogers, Thor, the X-Men, and the Fantastic Four. Disney unveiled the first full-length trailer for Avengers: Doomsday as part of its studio presentation to theater owners at CinemaCon.

The trailer opens with Downey Jr.’s green-hooded, metal-faced Doctor Doom preparing to invade the multiverse. The arrival of Doom — portrayed by an actor the world knows as Tony Stark — is designed to be a gut punch, and by all accounts it landed exactly as intended.

Downey Jr., who narrates part of the trailer in a vaguely Eastern European accent, took the stage alongside Evans to play the footage twice for the packed auditorium. Two screenings in one night. That alone tells you everything about the room’s reaction.

Doctor Doom catches Mjolnir — and the internet loses its mind

The single most talked-about moment is already clear: Thor and Doom face off, but Doom catches Thor’s magical hammer Mjolnir with his bare hands. In MCU canon, catching Mjolnir without being “worthy” is essentially impossible — making this a statement of power unlike anything seen since Thanos.

According to Variety, the footage is packed with crossover chaos from that moment onwards. Gambit (Channing Tatum) and Shang-Chi (Simu Liu) battle; Mystique (Rebecca Romijn) transforms into Yelena Belova, resulting in a Florence Pugh vs. Florence Pugh fight. It is the sort of multiverse absurdity that only Marvel could pull off with a straight face.

Patrick Stewart is back — and so is Captain America

Professor Xavier (Patrick Stewart) is seen looking out the X-Mansion’s window as a bright flash of light signals trouble outside. His presence confirms that the mutant timeline is now fully woven into the MCU’s main continuity, not kept at arm’s length as a cameo curiosity.

The biggest surprise, however, belongs to Chris Evans. The biggest moment comes when Steve Rogers makes his triumphant return and reunites with Thor. The Asgardian is shocked at his Avengers teammate’s arrival — given that Cap had gone back in time to grow old with his sweetheart Peggy Carter in Endgame.

It is still unclear how Cap is back, but he is clearly still worthy enough to pick up Thor’s hammer, just as he did during the Thanos battle in Endgame. The callback will delight anyone who has waited six years for this moment.

A hero roster unlike anything the MCU has attempted

The scale of this ensemble dwarfs even Infinity War. Similar to how Infinity War and Endgame brought together the Guardians of the Galaxy, the Wakandans and the Avengers, Doomsday intermixes Earth’s Mightiest Heroes with the X-Men, the Fantastic Four and the Thunderbolts.

After the Fantastic Four’s ship crossed into the MCU in the post-credits scene of Thunderbolts, we finally see Mr. Fantastic, Invisible Woman, Human Torch and Thing meeting the so-called New Avengers, consisting of Bucky Barnes, Yelena Belova, Sentry, Ghost, Red Guardian and U.S. Agent.

There is also a tense showdown between Black Panther’s Wakandan forces and Namor’s underwater Talokans after the two armies clashed in Wakanda Forever. Every thread Marvel has been spinning for years appears to be converging at once.

Why this matters for the MCU — and for cinemas

This trailer is not just a marketing moment; it is a lifeline for exhibition. According to The Hollywood Reporter, theater owners have been waiting six years for a Marvel event of this magnitude. A December 18 release gives cinemas a guaranteed box-office anchor heading into the holiday season.

The X-Men integration also resolves years of fan speculation. Rather than introducing the mutants slowly through solo projects, Marvel is placing them at the center of its biggest event film — immediately raising the stakes for every Fox-era character who survived the acquisition.

If you want to see how Marvel’s big-screen strategy compares to other blockbuster trailers dropping this year, our full coverage of The Hunger Games: Sunrise on the Reaping trailer is worth a read, as is our piece on Practical Magic 2, another major studio title building franchise buzz in 2026.

Reported from publicly available interviews and verified press sources. Last reviewed April 17, 2026.