Director Matt Shakman has confirmed that Robert Downey Jr. personally donned Doctor Doom’s costume for the mid-credits sequence in Marvel Studios’ newly released “The Fantastic Four: First Steps,” putting to rest speculation that the fleeting appearance relied on a body double. The cameo gives audiences their first on-screen glimpse of Downey in the role ahead of “Avengers: Doomsday,” due in cinemas on 18 December 2026. The actor underscored the connection by sharing a photograph from the “Doomsday” set on 26 July, signalling Marvel’s intention to knit its upcoming films more tightly together. Running 1 hour 55 minutes, “First Steps” introduces Reed Richards (Pedro Pascal), Sue Storm (Vanessa Kirby), Johnny Storm (Joseph Quinn) and Ben Grimm (Ebon Moss-Bachrach) as they battle the Silver Surfer (Julia Garner) and a world-devouring Galactus (Ralph Ineson). While Marvel has yet to announce a direct sequel, the Doctor Doom reveal positions the Fantastic Four at the centre of the studio’s next crossover arc, expected to culminate in 2027’s “Avengers: Secret Wars.”