A new trailer for Marvel's What If...? sees Peggy Carter become the first Avenger, Captain Carter, for the animated Marvel Cinematic Universe series. Carter first debuted in the interconnected franchise with its fifth installment, Captain America: The First Avenger, in which she acted as a love interest and fellow agent fighting against HYDRA, with Hayley Atwell portraying the character. The Golden Globe nominee would carry the role through her solo series Agent Carter that ran for two seasons on ABC as well as appearances in Captain America: The Winter Soldier, Agents of S.H.I.E.L.D., Avengers: Age of Ultron, Ant-Man and Avengers: Endgame.

Atwell is one of the large portion of MCU stars reprising their roles for What If...?, some of whom include Tom Hiddleston's Loki, Chris Hemsworth's Thor, Samuel L. Jackson's Nick Fury and Chadwick Boseman in his final performance as T'Challa. The animated series is based on the anthology Marvel comic line of the same name that explores alternate realities in which many characters live different lives and major events occur differently, including T'Challa becoming Guardians of the Galaxy leader Star-Lord, Killmonger becoming King of Wakanda and zombified versions of heroes. As the series nears its premiere, Disney+ and Marvel are looking to keep anticipation high.

Related: Why The MCU Needs Peggy Carter's Captain Britain Movie

With just a day remaining until the series' premiere on Disney+, Marvel Studios has unveiled a new trailer for What If...?. The video features a screen of computer text referring to Steve Rogers' transformation into the first super soldier, though changes gears to explore what would happen with Peggy taking the serum instead. Check out the exciting new trailer below:

Click here to watch the trailer

Captain Carter has been one of the more prominent alternate universe stories featured in the marketing campaign for What If...? and it's very easy to understand why. Since Atwell's debut in Captain America: The First Avenger, fans have fallen in love with both the character and her performance, establishing her as a powerful equal to the titular hero as much as his romantic interest. Though the character's live-action story has seemingly come to a close after the time-traveling events of Avengers: Endgame, the confirmation of Pegg's return in What If...? and transformation into the super soldier Captain Carter has created much anticipation amongst fans.

Those who are looking forward to the arrival of Captain Carter in What If...? also have a lot of anticipation for the character's MCU future after season 1 of the series. With series producer Brad Winderbaum recently confirming Captain Carter's story will carry over into future seasons and Atwell also confirmed to return, the latest Marvel superhero isn't going anywhere anytime soon. The wait is almost over for her arrival as What If...? premieres on Disney+ tomorrow.

More: Every Phase 1 Character Returning In Marvel's What If...?

Source: Marvel Studios