Marvel fans got to see almost all of the Avengers in action in Avengers: Infinity War... but one of them was notably off his game the whole time. There has been a lot of speculation about what could be going on with the Hulk at this point in the Marvel Cinematic Universe, and now a new fan theory is proposing that the Bruce Banner/Hulk we see before us is actually not the Hulk at all! So... was the Hulk replaced by a Skrull imposter, or perhaps by some other imposter that we've seen before? Let's break down this game-changing new theory.
Things have been getting kind of weird and complicated with the Hulk ever since Thor: Ragnarok. In that movie, the Hulk completely took over Bruce Banner's body and refused to give it back, and he also showed a ton more personality than we had ever seen from the big green guy. Things only got more complicated in Avengers: Infinity War, when Thanos handily beat the Hulk down and then the Hulk refused to come out to protect Bruce Banner in the final battle. Infinity War director Joe Russo explained this alarming new development by saying that the Hulk was tired of being used only for his strength by Bruce Banner, but some fans think that there is something much more insidious going on with the character.
Ahead of Thor: Ragnarok's release, Mark Ruffalo revealed that the Marvel Cinematic Universe is currently in the middle of a major story arc for the Hulk. Ruffalo said that Ragnarok, Infinity War, and next year's Avengers 4 make up a sort of trilogy for the Hulk, which of course, has fans wondering if there's a big surprise concerning the Hulk waiting for us in Avengers 4. Given how out of character the Hulk has been acting in the past two movies, a new theory is that the Bruce Banner in Ragnarok and Infinity War is not the same guy who flew off into space at the end of Avengers: Age of Ultron.
There's one theory that claims Loki was somehow able to use his shapeshifting powers to cheat death yet again and turn himself into a fake Bruce Banner, but this seems like a bit of a reach. A more recent theory is that Bruce Banner was replaced by a Skrull imposter after blasting off in a spaceship at the end of Age of Ultron, and it is this imposter Hulk that we see throughout Ragnarok and Infinity War.
If you are not familiar, the Skrulls are an alien race capable of shapeshifting, and we know that they are about to be a big part of the Marvel Cinematic Universe since Captain Marvel is introducing them as the movie's main villains. There is also speculation that a future Avengers movie may be based on the popular "Secret Invasion" comic arc, which focuses on the Skrulls revealing that they have taken multiple heroes and replaced them with imposters. If that is the plan, then this would probably be the perfect time to start laying the groundwork.
If the Hulk really is a Skrull, then it would explain how he is acting a bit different these days than he was in his pre-Ragnarok appearances. There is also some precedence for Skrull's gaining the powers of the being they shapeshift into, although they don't always get the hang of controlling erratic powers like the Hulk's right away. That might explain why Bruce Banner is suddenly at odds with the Hulk and unable to fully use his powers. Mark Ruffalo said that the final part of this Hulk story is coming in Avengers 4, so we will definitely find out next summer if this turns out to be true or not.