Yes, that mysterious cloaked figure in Fantastic Four is indeed played by Robert Downey Jr. – as confirmed by the director himself.

Disney/Marvel Studios’ “The Fantastic Four: First Steps” is having a, well, fantastic start to its box office run.

Without his planet-devouring space vessel, it'll take the now-stranded Galactus millions of years to make his way back to the quartet's home world, and that's even if he's capable of doing so.