MCU Phase 4: Every Single Character Confirmed (So Far)

10. Peggy Carter/Captain Britain (Hayley Atwell) - What If?

Peggy Carter returns. Cancellation can't end her. Death can't end her. A happy ending can't even end her. She's coming back to play a part in What If...? too.

D23 revealed an outline of the first episode as well as some unfinished animation showing Peggy Carter being given the super soldier serum and taking on the mantle of Captain Britain - though she's being referred to as Captain Carter. She's in the same story in which Steve Rogers wears the giant mech suit Howard Stark develops.