Ryan Reynolds reportedly went undercover in a Deadpool costume at San Diego Comic-Con, mingling with unsuspecting fans and posing for photos before making his scheduled appearance on the Avengers: Doomsday panel. The stunt drew attention for its spontaneity, with Reynolds said to have moved through the convention without the usual trappings of celebrity security, describing the experience as having "no handlers, no security, no ropes."

The surprise appearance let ordinary attendees interact with the actor as if he were simply another costumed fan, adding to the buzz already surrounding his role in the upcoming Avengers instalment. Details of the panel itself, including any Doomsday-related announcements, followed the low-key Deadpool cameo, which quickly became a talking point among convention-goers and on social media.