Robert Downey Jr has announced his shock return to the Marvel Cinematic Universe (MCU), stunning fans when he was dramatically unmasked as the villainous Doctor Doom.

The longtime Iron Man actor was unveiled to huge applause at a MCU panel at San Diego Comic-Con on Saturday night, where it was announced he would take up the role in at least one upcoming Avengers movie.

In footage of the event shared on X by the official Marvel Studios account, Downey Jr told a room full of excited fans: “New mask, same task.”

Downey Jr kickstarted the superhero craze with his Iron Man debut in 2008, going on to star as the character in eight further MCU films.

Avengers Endgame and Infinity War directors Joe and Anthony Russo confirmed they are on board to direct Downey’s next MCU appearance, titled Avengers: Doomsday.

“When we directed Avengers: Endgame, Joe and I truly believe d that it was the end of the road for us in the Marvel Cinematic Universe,” Anthony Russo told the Comic-Con crowd.

“In the time since, through a very special story, Joe and I have come to potentially see a road forward with you.”

The panel also confirmed Harrison Ford’s involvement in the next Captain America film.

Captain America: Brave New World, starring Anthony Mackie in the role formerly held by Chris Evans, is scheduled for release next year.