Robert Downey Jr returns as Doctor Doom in Marvel’s Fantastic Four post-credits scene

Marvel’s First Family has officially landed in the Marvel Cinematic Universe. But it’s who arrives after the credits roll that’s turning heads.

The Fantastic Four: First Steps, which opens wide Friday, introduces audiences to Reed Richards (Pedro Pascal), Sue Storm (Vanessa Kirby), Ben Grimm (Ebon Moss-Bachrach), and Johnny Storm (Joseph Quinn) in a retrofuturistic, alternate-Earth story. The film marks the kickoff of Marvel’s Phase 6 and teases the beginning of its next big bad: Doctor Doom.

The post-credits moment in question unfolds quietly. It’s four years after the team’s climactic showdown with Galactus. Sue Storm is reading to her young son, Franklin Richards. As she steps away to grab another book, something feels off. When she returns, she finds a mysterious cloaked figure beside Franklin holding a metallic mask. Marvel veterans didn’t need a face reveal as the green cloak said it all.

Doctor Doom has entered the MCU

This marks the character’s first formal appearance in Marvel Studios’ continuity, and his entrance is a personal one, not with armies or threats, but a silent encounter with a child who might be one of the most powerful beings in the multiverse.

Fans of the comics will know Franklin Richards is no ordinary kid. Born to cosmic-powered parents, Franklin has been known to reshape reality itself. Which may explain Doom’s interest.

The arrival of Doom also signals a major pivot. Originally, Kang the Conqueror was slated to be the saga’s central threat. But after actor Jonathan Majors was convicted in 2023, Marvel shifted focus, choosing to introduce Doom as the looming force behind the upcoming multiversal saga.

In a bold casting choice, Robert Downey Jr., once Iron Man himself, now returns to the franchise, not as a hero, but as Victor Von Doom.

Vanessa Kirby recently praised Downey’s transformation: “It’s some of the most amazing work I’ve seen. He lifts everyone around him.” Joseph Quinn echoed that sentiment, calling Downey “deep, kind, and a real leader on set.”

Avengers: Doomsday, scheduled for December 18, 2026, is already filming in the UK under Joe and Anthony Russo. Kevin Feige recently confirmed that the film is being rewritten and refined daily. Before Avengers: Doomsday, Marvel will debut Wonder Man on Disney+ in December and release Spider-Man: Brand New Day in July 2026.