Robert Downey Jr.’s Doctor Doom just got the most exciting tease yet from an unexpected Avengers: Doomsday co-star. One actor revealed what it was really like watching Downey bring the iconic Marvel villain to life on set.

Ebon Moss-Bachrach reveals the most surprising actor in Avengers: Doomsday

Ebon Moss-Bachrach has teased Robert Downey Jr.’s Doctor Doom performance in Avengers: Doomsday during a conversation with Entertainment Tonight. The actor plays Benjamin Grimm after first appearing in The Fantastic Four: First Steps earlier this year. He called the MCU set “a carnival of really great actors” who are “dressed sort of silly.”

Moss-Bachrach singled out Downey when asked who surprised him the most on set. He shared, “I guess in scenes, Downey is such a surprising, playful, mischievous actor. I found him to be maybe the most sort of surprising or the most unknowable, in a good way, in an acting sort of way.” These remarks provide early insight into how Downey is tackling the legendary Marvel villain.

Downey kicked off the MCU in 2008 by starring as Tony Stark in Iron Man. His journey as the character ended with his heroic death in 2019’s Avengers: Endgame. He now makes his grand return to the franchise as the film’s central antagonist, Doctor Doom.

The public has not yet seen a full Avengers: Doomsday trailer featuring Downey’s portrayal. His only onscreen appearance as Doom came in The Fantastic Four: First Steps post-credits scene. That brief moment showed him beside Franklin Richards, though he remained silent throughout.

Previously, Julian McMahon portrayed Doctor Doom in the 2000s Fantastic Four films, while Toby Kebbell took over for the 2015 reboot.

Marvel Studios originally planned the fifth Avengers film as The Kang Dynasty, starring Jonathan Majors. The studio later pivoted to Avengers: Doomsday following Majors’ legal issues. Kevin Feige has stated that the shift from Kang to Doom was already underway before Quantumania hit theaters.

Avengers: Doomsday arrives on December 18, 2026, alongside Dune: Part Three.

Originally reported by Anubhav Chaudhry on SuperHeroHype.com.