Ryan Reynolds made a surprise, in-costume appearance as Deadpool during Marvel's Avengers: Doomsday panel at San Diego Comic-Con, reigniting fan speculation over whether his character actually features in the upcoming film. Rather than settling the debate, his cryptic exchange with Robert Downey Jr and the cast left the answer deliberately ambiguous, generating conflicting evidence both for and against his involvement.

Reynolds, disguised as a "cosplayer" named Ricky, was called up by Downey Jr and posed pointed questions to director Anthony Russo and co-star Paul Rudd about filming status and reshoots, referencing an unresolved Deadpool & Wolverine joke about a tearful Thor. He reportedly spent the day mingling incognito with other Deadpool cosplayers before revealing himself, and skipped a separate Apple TV panel to keep his SDCC surprise secret, fuelling further theories about his role in the film.