Next year, the Marvel Cinematic Universe is finally introducing the Skrulls in Captain Marvel, and just like their comic book counterparts, these versions of the aliens can shapeshift. As a result, they've disguised themselves among us in the penultimate Phase 3 movie in order to conquer Earth and gain an edge in their never-ending conflict with the Kree. However, because Captain Marvel takes place over a decade before the modern MCU kicked off, and because the 2007 Secret Invasion storyline has kept comic book fans paranoid, there's been speculation about if any familiar MCU characters are actually Skrulls, and Thaddeus "Thunderbolt" Ross is the latest suspect.
Like his comic book counterpart, William Hurt's version of Thunderbolt Ross was obsessed with capturing Bruce Banner in The Incredible Hulk, but because there are obstacles in place preventing Marvel from delivering another standalone Hulk movie, Ross' personal feud with Banner has collected dust. As a result, Ross, now the U.S. Secretary of State, turned his attention to regulating all enhanced individuals via the Sokovia Accords in Captain America: Civil War, a position he didn't back down from during Avengers: Infinity War. But one Redditor believes that not only is the Ross we've been following along with all this time a Skrull, but there's more to his obsession with The Hulk than meets the eye.
First off, Skrull Ross was determined to capture Bruce Banner because he knew having the Green Goliath around would be trouble for another Skrull invasion, which is also why he worked to split up the Avengers. More importantly, Skrull Ross wanted to collect Hulk's DNA to infuse within himself. Since Disney doesn't have the Fantastic Four film rights yet, they can't use the Super Skrull character yet, but this would allow for a different kind of enhanced Skrull to pose a physical threat to our heroes.
This is certainly an interesting theory, and I'm also intrigued by this fan's other suggestion that Ross Skrull should instead inject himself with Abomination's DNA, giving him a look similar to Emil Blonsky's monstrous persona. That said, I don't necessarily buy that Thunderbolt Ross has been a Skrull since The Incredible Hulk. As one of the commenters on the Reddit thread pointed out, Ross was "far more aggressive and less diplomatic" in The Incredible Hulk than he was in Captain America: Civil War, so perhaps the replacement occurred sometime between those two movies. As a general, Ross Skrull could only go so far dealing with Earth's superhumans, but in the political realm, he had more freedom to carry out his agenda, i.e. the Skrull Empire's wishes. As for giving himself a power boost, if Ross Skrull were to be physically transformed, that's be an intriguing way for the MCU to adapt Red Hulk, though I doubt he would be crimson-colored.
Not only do we not know yet if Thunderbolt Ross survived the Thanos snap, there's no guarantee yet he's returning in Avengers 4 or another upcoming MCU movie. So while this is an interesting theory, the chances of it panning out are slim at this point. That said, I'm still for the idea that someone established in this universe could actually be a Skrull. This alien race is too important to be retired after just one movie.
We'll see how the Skrulls' attempt to conquer Earth in the MCU in the mid-1990s unfolded when Captain Marvel is released on March 8, 2019.