Marvel Studios has released the official trailer for Marvel's What If...?, the new animated series that reimagines how major events could have played out differently in the Marvel Cinematic Universe. A new poster has also been released which features the tagline, "One question changes everything." The new trailer, which features the actual actors from the MCU reprising their roles by doing voiceovers for the series, can be watched below.

Creating a "multiverse of infinite possibilities," What If...? brings back many fan favorites in all-new scenarios. This includes Hayley Atwell returning as Peggy Carter in an alternate reality scenario that imagines her taking the super soldier serum instead of Steve Rogers. The late Chadwick Boseman also provides his final performance as T'Challa for the animated series, as he had recorded his lines for the show prior to his death last year. A look at his return is also shown in the new trailer, imagining the Black Panther superhero becoming Star-Lord.

Meanwhile, other actors from the MCU reprising their roles for the series include Samuel L. Jackson, Josh Brolin, Karen Gillan, Michael B. Jordan, Chris Hemsworth, Tom Hiddleston, Taika Waititi, Mark Ruffalo, Paul Rudd, Michael Rooker, Natalie Portman, Sebastian Stan, Jeff Goldblum, Jeremy Renner, Neal McDonough, Dominic Cooper, Toby Jones, Sean Gunn, Frank Grillo, and more. Jeffrey Wright (Westworld, The Batman) also voices the Watcher, a character that essentially serves as the narrator of the animated series.

Marvel's What If Poster

"In the comics, he's an observer-and then some," Wright said of his role, via Disney's D23 Magazine. "Here, in the first season, he starts off as an observer, but he gradually becomes more compelled by what he watches. There are infinite possibilities with this series within the MCU. I'm open to all of it. One thing I think we're realizing with Marvel and Kevin Feige's leadership is that these are broad, broad canvasses they're painting on. I don't even try to anticipate, so I'm just open to all of it - as the Watcher would be."

Bryan Andrews directs What If...? with AC Bradley serving as head writer. Kevin Feige, Louis D'Esposito, Victoria Alonso, and Brad Winderbaum executive produce. This is the first animated series for Marvel Studios, and feeling confident in how it will be received, the studio has already begun developing a 10-episode second season. While we can see many of the confirmed characters appearing in season 1, Bradley has teased many surprising cameos as well.

"Spoilers! But I can say that there are more than a few surprising MCU cameos... and characters can and do pop up in more than one episode!" the writer wrote on Twitter in January.

"Kevin said that we will be exploring every movie in a new way, but not every episode is about one movie if that makes sense," Bradley added, via DiscussingFilm. "On the reel [shown at D23 Expo], there is this image of a Star-Lord T'Challa because we wanted to see what if the worlds of Black Panther and the Guardians of the Galaxy collided? That was taking two universes, two to three movies, kind of twisting them in new ways."

Marvel's What If...? will be released on Aug. 11, 2021, exclusively on Disney+. The new trailer for the freshman season of What If...? comes to us from Marvel Studios.