(Image: Marvel Studios)
While most of the core cast for "Avengers: Doomsday" was revealed in late March, Marvel Studios is clearly holding back some surprises to maintain buzz, planning to unveil them gradually during later promotional phases. However, not every surprise stays under wraps. Kathryn Newton, who plays the third-generation Ant-Man, Cassie Lang, in "Ant-Man and the Wasp: Quantumania," recently seemed to prematurely leak her involvement in "Doomsday."

(Image: Marvel Studios)
Newton recently posted a photo on social media with a friend, in which she was wearing a hat adorned with a bow and featuring the "Doomsday" movie title logo. Fans quickly concluded that Newton is likely part of the "Doomsday" cast, as such merchandise is typically distributed to production crew members and rarely given as gifts to outsiders not involved in the film. This strongly suggests Newton is indeed a member of the "Doomsday" team.