Marvel Studios has already told fans plenty about Avengers: Doomsday (2026), but the studio may still be keeping some of the movie's biggest surprises out of sight.
The next Avengers crossover arrives in theaters on December 18, and principal photography has already wrapped. Even so, additional filming has reportedly continued as Marvel assembles the movie.
For a blockbuster this large, reshoots aren't necessarily unusual. But a new insider report claims this latest round has an especially interesting purpose.
Marvel may be adding even more cameos to Doomsday. If that's true, the question quickly becomes who could still join a cast that's already packed with Marvel favorites.
‘Avengers: Doomsday’ Is Already Packed With Marvel Stars
Joe and Anthony Russo are back behind the camera for Avengers: Doomsday (2026) after directing Avengers: Infinity War (2018) and Avengers: Endgame (2019).
They're working with an enormous collection of Marvel characters this time around.
Robert Downey Jr. will return to the MCU, but not as Tony Stark. Instead, he'll step into the role of Victor von Doom.
The confirmed cast includes:
- Doctor Doom (Robert Downey Jr.)
- Thor (Chris Hemsworth)
- Steve Rogers (Chris Evans)
- Captain America/Sam Wilson (Anthony Mackie)
- Loki (Tom Hiddleston)
- Bucky Barnes (Sebastian Stan)
- Shang-Chi (Simu Liu)
- Shuri (Letitia Wright)
- Ant-Man (Paul Rudd)
- Yelena Belova (Florence Pugh)
- Mister Fantastic (Pedro Pascal)
- Invisible Woman (Vanessa Kirby)
- Human Torch (Joseph Quinn)
- The Thing (Ebon Moss-Bachrach)
- Professor X (Patrick Stewart)
- Magneto (Ian McKellen)
- Cyclops (James Marsden)
- Nightcrawler (Alan Cumming)
- Mystique (Rebecca Romijn)
- Gambit (Channing Tatum)
That's an enormous roster before Marvel potentially adds anyone else.
Marvel Reportedly Isn't Finished With the Cast
Insider Daniel Richtman recently reported that Marvel Studios is “still doing reshoots” on Avengers: Doomsday (2026).
Richtman also claimed Avengers: Secret Wars (2027) isn't expected to begin filming until “the end of September.”
That raised an obvious question. Why is Marvel continuing work on Doomsday with its next Avengers movie getting closer to production?
Richtman offered a possible answer in a follow-up report, claiming Marvel is “adding a lot of cameos” to Doomsday during additional photography.
Marvel hasn't confirmed that report, so there's no official word on who those cameos might involve.
Still, the Multiverse gives the studio plenty of possibilities. Marvel could add MCU characters missing from the announced lineup or draw on familiar faces from other Marvel movies.
‘Secret Wars’ Could Factor Into the Additional Filming
There could be another benefit to continuing work on Doomsday right now.
With Avengers: Secret Wars (2027) expected to begin production soon, Marvel is preparing the sequel while finishing its predecessor.
Additional photography could help the studio tighten the connections between the movies. Marvel could adjust dialogue, introduce characters sooner, or add story elements that become important in Secret Wars.
Scheduling could also play a role. Coordinating this many major actors isn't simple, making multiple rounds of additional filming understandable.
But the reported cameo additions create another question: Which missing Marvel characters could appear?
Some Original Avengers Remain Unaccounted For
Jeremy Renner immediately stands out.
The Hawkeye actor recently sparked speculation by sharing a video of his character's costume set to music associated with Hawkeye. That doesn't confirm Renner is returning, but the timing gave fans something to discuss.
Mark Ruffalo's Hulk is another obvious possibility. Bruce Banner survived Avengers: Endgame (2019), but Ruffalo isn't part of the announced Doomsday lineup.
Elizabeth Olsen's Scarlet Witch is missing, too.
Wanda Maximoff seemingly died during Doctor Strange in the Multiverse of Madness (2022). Still, the uncertainty surrounding her fate has kept theories about an eventual return alive.
Those three aren't the only possibilities.
Marvel Could Reach Beyond the Current MCU
If Marvel wants its cameos to lean heavily into the Multiverse, several familiar characters could enter the conversation.
Ryan Reynolds' Deadpool and Hugh Jackman's Wolverine are two obvious candidates following Deadpool & Wolverine (2024). Marvel didn't include either actor in its original Doomsday cast presentation.
Tobey Maguire could provide an even bigger surprise.
Maguire returned as Spider-Man in Spider-Man: No Way Home (2021), showing that his version of the character can cross into the MCU's Multiverse storyline.
Of course, none of those appearances has been confirmed.
Marvel Could Be Saving Its Biggest Surprises
Marvel has already assembled an enormous cast for Avengers: Doomsday (2026), making Richtman's latest claim even more intriguing.
If Marvel really is “adding a lot of cameos,” the final movie could feature significantly more familiar faces than its announced roster suggests.
Hawkeye, Hulk, Scarlet Witch, Deadpool, Wolverine, and Spider-Man remain theories rather than confirmed additions.
With the December 18 release approaching, Marvel may have plenty left to reveal — or it could try to keep those surprises hidden until audiences finally see Avengers: Doomsday (2026).
