When Entertainment Weekly asked Fantastic Four: First Steps director Matt Shakman if Downey Jr. filmed that post-credits scene, the filmmaker pleaded the fifth. "For others to talk about," he teased. However, Shakman did reveal that it was the Russo brothers who helmed the post-credits scene since it was shot for Avengers: Doomsday.

Robert Downey Jr's Doctor Doom has finally stepped into the Marvel Cinematic Universe. In one of the most crucial credit scenes for 'The Fantastic Four: First Steps,' viewers were introduced to the masked metal villain,