Robert Downey Jr. and Pedro Pascal Swap Places for Halloween With Mister Fantastic and Doctor Doom Costumes

Halloween had no shortage of viral costumes, but Robert Downey Jr. and Pedro Pascal might have taken the crown by swapping places as Mister Fantastic and Doctor Doom.

Downey Jr. set Marvel feeds on fire late last night when he posted video of him and Pascal sharing their night dressed as their characters in next month's Avengers: Doomsday. Instead of playing Victor von Doom, though, he dressed up in Reed Richards' retro-themed blue outfit, with Pascal dropping his superhero attire to sport Doom's iconic metal mask.

It looks like Downey put a bit more effort into his Halloween costume, considering Pascal is wearing jeans and a sweatshirt, but the effect is still there. Finding a convincing replacement for Doctor Doom's magical get-up probably would have been more trouble than it's worth anyway. You can see Downey's video below.

They're the variants no one expected to see, but still the ones they got this Halloween. With Doomsday now just weeks away, we'll likely only see its many, many stars taking to social media to spread the word.

That said, this was a tiny bit more than a cute marketing stunt. While it was fun to see the two team up for a quick costume swap, Downey and Pascal still took the time to hit the streets and greet trick-or-treaters. Pascal shared a video of him and the Doctor Doom actor out on the town, walking amongst the crowd, on his Instagram story.

If that wasn't evidence enough, X/Twitter user Patrick Oneill shared pictures of him and two children greeting them in full Star Wars attire. With one kid dressed up as Pascal's character, the Mandalorian, Downey reportedly made a joke about the encounter by inviting them to come meet the "real" Mandalorian.

Robert Downey Jr. and Pedro Pascal dressed up as Doctor Doom and Mister Fantastic for Halloween. 😭 https://t.co/YEK8jjiXjx

— Drew Smith (@DrewDisneyDude) November 1, 2026

Avengers: Doomsday premieres December 18, 2026. When it marks the beginning of the end for this chapter of the Marvel Cinematic Universe, it will feature a cameo from Project Hail Mary's Sandra Hüller. It will also mark the final on-screen appearance of Sir Patrick Stewart. For more, you can check out how one recent poster highlighted Doctor Doom and his three Latverian witches.