The MCU Already Introduced The X-Men, But A Lot Of People Missed It

Marvel Studios is apparently playing the prank of the century with the longest casting announcement in cinema history for "Avengers: Doomsday," revealing a bevy of performers (or, more accurately, chairs bearing their names) one at a time in a special livestream over the course of several hours ... though one name in particular is causing many fans to scratch their heads. In addition to all the usual suspects, from legacy Avengers cast members like Chris Hemsworth to the A-list cast of the upcoming "The Fantastic Four: First Steps" to several members of "Thunderbolts," the addition of longtime character actor Kelsey Grammer came as a surprise to many. Not only will the "Frasier" star will apparently be joining the action, but he'll be doing so by reprising his role as Dr. Hank McCoy/Beast from the original "X-Men" franchise. (It's worth noting that Patrick Stewart, Ian McKellen, and a number of other X-Men actors were also announced as returning, many of them after this article was initially published.) 

And yet, this isn't even the first time Grammer will be appearing as such in the Marvel Cinematic Universe. While practically every other name and role ought to be accounted for in this excruciatingly drawn-out announcement, the same can't quite be said for this. General audiences would be forgiven for forgetting — or being straight-up unaware — that Grammer's Beast actually first returned in 2023's "The Marvels." The "Captain Marvel" sequel saved this tease for its post-credits scene, officially uniting the MCU and "X-Men" franchises long before "Deadpool & Wolverine" ever did. Unfortunately, even this supposedly game-changing twist wasn't enough to save "The Marvels" from its ignominious fate as a theatrical flop, and the multiversal connection largely fell by the wayside.

Until now, that is. Apparently, "Doomsday" will somehow incorporate Grammer's Beast into the story and, in the process, also remind fans of a movie that many casual moviegoers simply never saw. We're left to wonder whether this will pose a certain complication or two for what might go down as Marvel's most highly-anticipated blockbuster ever.

Honestly, we're still a little bummed out over "The Marvels." Despite Iman Vellani's best efforts, the misshapen sequel ultimately felt like a disappointment upon release (as you can read in our review here) due to a number of factors — chief among them, of course, being the significant reshoots that clearly interfered with writer/director Nia DaCosta's original vision. Although the film went on to become Marvel's lowest-grossing film ever, those who tuned in were treated to a cosmic, body-swapping adventure that brought together the unexpectedly delightful trio of Kamala Khan (Vellani), Brie Larson's Carol Danvers/Captain Marvel, and Teyonah Parris' Monica Rambeau from the Disney+ "WandaVision" series.

By the end of the film, the trio puts their differences aside to save the day ... though not before a last-minute twist ended the film on an uncertain note. While out in the far reaches of space, an "incursion" of different universes threatens to unleash a wormhole that could destroy everything in the immediate vicinity. Our heroines leap into action to prevent this from happening, though not before Monica finds herself trapped and separated from the rest of her friends. All they can do is watch helplessly as the wormhole closes and she disappears completely from their own reality. This being the MCU, however, dead isn't truly dead unless you actually see a body (and, in many cases, even in spite of that).

That leads to the post-credits sequence, in which fans were given the biggest tease yet about the multiverse. Disoriented, Monica wakes up in some strange lab setting with a pair of unusual characters watching over her — those being Lashana Lynch's alternate-universe Maria Rambeau/Binary, and Kelsey Grammer's Dr. Hank McCoy/Beast. At the time, the reveal didn't feel all that meaningful as it remained unclear when (or if) this would ever be followed up on. Now, however, "Doomsday" may be stuck filling in the gaps.

Call it a rite of passage for any "Avengers" movie. Because of the extremely serialized nature of the MCU, every major crossover movie has had to do some serious heavy-lifting in order to address various characters, subplots, and MacGuffins carrying over from one movie (or Disney+ series) to another. 2012's "The Avengers" had to act like moviegoers hadn't seen all of the various Phase One films, "Captain America: Civil War" quickly brought casual fans up to speed on several aspects of the MCU that they may not have been familiar with already, and "Avengers: Infinity War" and "Avengers: Endgame" were able to get away with assuming that everyone was at least somewhat familiar with the majority of the superhero franchise by then.

The formidable task facing "Avengers: Doomsday" feels a little different, though. Not only will returning directors Joe and Anthony Russo have to explain why the heck Robert Downey, Jr. is suddenly back as the villainous Doctor Doom, along with a boatload of other multiversal shenanigans. But the blockbuster, with a full cast rumored to soar close to 50 main actors, will have to find time and space to essentially do a "Previously on the MCU" segment for all the audiences who never managed to get around to a relatively more minor film like "The Marvels." And if Kelsey Grammer's presence as Beast is confusing enough, what if that means even more original "X-Men" actors will be coming along for the ride (and with the announcement of Patrick Stewart, that sure seems likely)? It's one thing to build out a whole storyline involving Doctor Doom, but stopping the plot in its tracks to wax nostalgic on the previous "X-Men" movies on top of that? That's a tall order.

We'll find out when "Avengers: Doomsday" hits theaters on May 1, 2026.