Warning: This post contains spoiler details for Marvel’s The Fantastic Four: First Steps and Avengers: Doomsday.
The post‑credits scene of Marvel’s The Fantastic Four: First Steps features a man in a green cloak holding a metal mask and interacting with Franklin Richards. Director Matt Shakman confirmed that the character seen in the credits was Robert Downey Jr.’s Victor Von Doom/Doctor Doom.

According to insider Alex P (via Cosmic Circus), Downey Jr.’s Doctor Doom is from the same universe as the Fantastic Four of Earth‑828.
Speaking on the Phase Hero Podcast, Shakman confirmed that it was actually Downey Jr. in The Fantastic Four: First Steps mid‑credits scene — not a stand‑in or a CGI double.
In The Fantastic Four: First Steps post‑credits scene, set four years after Galactus’s defeat on Earth‑828, Sue Storm searches for Franklin’s favorite book in the Baxter Building. When she returns, she sees a caped man holding Franklin — Doctor Doom, with his mask in Franklin’s hands. The scene ends with the message: “The Fantastic Four will return in Avengers: Doomsday.”

In an interview with ComicBook.com, Shakman revealed that Joe and Anthony Russo (directors of Avengers: Doomsday) filmed the post‑credits scene for The Fantastic Four: First Steps. The sequence was shot while Avengers: Doomsday was in production earlier this year.
Shakman said, “Not at all, especially when I’m handing them off to the Russo brothers, who are amazing at what they do and they’re lovely, generous people.” He added, “They were very involved, and as we were making this film, they wanted to visit our sets and watch scenes as they were coming together and get to know these characters so they could treat them well, do right by them in the next movie. They’re really good protectors of these characters as well. I often think of working at Marvel as like running a relay race. You pass the baton, you run as hard and fast as you can with it for that section of the race that belongs to you, and then you pass that baton. I passed it on to Joe and Anthony, and they’re off and running, and that’s great.”
In Avengers: Doomsday, the MCU begins the beginning of the end. As the multiverse nears total collapse, the Avengers assemble to face their greatest challenge yet—incursions, catastrophic collisions between realities that could destroy the entire multiverse. Earth’s Mightiest Heroes must race against time to save their reality while confronting the powerful figure behind it all—Victor Von Doom (Downey Jr.).
Here’s the plot details for The Fantastic Four: First Steps:
Marvel Studios’ The Fantastic Four: First Steps introduces Reed Richards / Mister Fantastic (Pedro Pascal), Sue Storm / Invisible Woman (Vanessa Kirby), Johnny Storm / Human Torch (Joseph Quinn), and Ben Grimm / The Thing (Ebon Moss-Bachrach) as they face their most daunting challenge yet. Forced to balance their roles as heroes with the strength of their family bond, they must defend Earth from a ravenous space god called Galactus (Ralph Ineson) and his enigmatic Herald, Silver Surfer (Julia Garner). And if Galactus’ plan to devour the entire planet — and everyone on it — weren’t bad enough, it suddenly gets very personal.
The film also stars Paul Walter Hauser, John Malkovich, Natasha Lyonne, and Sarah Niles. Directed by Shakman, produced by Kevin Feige, and executive produced by Louis D’Esposito, Grant Curtis, and Tim Lewis.
The Fantastic Four: First Steps was released in U.S. theaters and IMAX on July 25, as the first film in Phase Six of the MCU.
Source: Phase Hero Podcast
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