Warning: Spoilers Ahead For Doctor Strange In The Multiverse Of Madness!

The Secret Invasion Disney+ series will see a popular storyline from the comics adapted into the MCU. The story will follow Nick Fury's attempts to stop a group of Skrulls from taking over Earth with their abilities to shapeshift.

The show will no doubt have fans questioning which heroes are themselves and which are simply Skrulls in disguise. But there is also the possibility that the Skrulls have already been posing as some of the MCU's heroes in some of their past appearances without fans knowing.

Nick Fury

Nick Fury with Triangle Bead in Avengers Age of Ultron

At the end of exactly when that switch was made.

RELATED: 9 Fan Theories for Secret Invasion, According to Reddit

But some detail-oriented fans pointed out an interesting point in Avengers: Age of Ultron, he is shown cutting a sandwich diagonally. It is such a small detail that it could hint at something more.

Bruce Banner

Captain Marvel and Bruce Banner as holograms in Shang-Chi post-credit scene

While introduce the new MCU hero, there were some fun cameos as well. In the mid-credit scene, Shang-Chi discusses the origins of the Ten Rings with Captain Marvel and Bruce Banner via hologram.

However, when Banner was last seen, he was in his Smart Hulk form and seemed as though he was going to stay that way. Seeing Banner in human form could indicate that he was actually a Skrull and the shapeshifter thought it would be easier to pose as a human than Hulk.

Kingo

Kingo preparing for battle in Eternals.

Eternals introduced a lot of new heroes to the MCU, but Kingo stood out as the scene-stealer of the movie. The cosmic warrior turned Bollywood star was a pivotal member of the team, but he also made a surprising decision in the final act.

RELATED: 10 Things MCU Fans Should Know About the Skrulls

When Ikaris reveals his plans to allow the Emergence to happen, Kingo decides he is right and sits out the final battle. He then returns in the finale to reunite with his friends. But with Kingo's sudden departure and then returning without his trusty valet Karun, it does raise questions about Kingo.

James 'Rhodey' Rhodes

Don Cheadle in The Falcon and the Winter Soldier

Rhodey will soon be headlining his own solo series on Disney+ as well with the The Falcon and the Winter Soldier. Rhodey appears for only a scene as he s Sam Wilson as he hands over Captain America's shield.

For Rhodey to appear and then disappear so quickly, not getting involved in the military operation at the center of the series, could suggest that wasn't Rhodey at all. That could be the Skrulls attempting to influence someone who stands to inherit the new title of Captain America.

Secretary Ross

Captain America confronts Thaddeus Ross in Avengers Infinity War

After making his MCU debut in Avengers: Infinity War.

Despite this, Ross was a surprise guest at the funeral of Tony Stark. He and Stark never seemed to like each other very much so it is a bit odd to see him there. This could point to Ross being a Skrull. Sadly, following the death of actor William Hurt, Ross will likely not be seen in the MCU in the future.

Darcy Lewis

Darcy looking at Vision in WandaVision

Though Darcy Lewis was seen as an WandaVision seemed to redeem the character. She was a funny, smart, and helpful sidekick to the heroes and it will be interesting to see where she pops up next.

Darcy is last seen helping the heroes take down the corrupt Director Hayward in Westview but then suddenly disappears from the climax. It is revealed that a Skrull was posing as a SWORD agent during the raid of Westview so it is possible Darcy was among them.

America Chavez

America Chavez running

Though she has only just made her debut in America Chavez is already a new favorite MCU character. The climax of the movie sees her finally gaining control of her multiverse-traveling abilities so it would stand to reason she would go out seeking her mothers whom she lost years ago.

Instead, America is seen training to be a sorcerer at the Kamar Taj. It is possible that this America is actually a Skrull looking to infiltrate the powerful order of sorcerers. That might explain why America was struggling with her magical abilities.

Happy Hogan

Happy Hogan in a car looking at Spider-Man in No Way Home.

Happy Hogan has been a helpful ally to Peter Parker in the solo Spider-Man movies. But their final scene together in Spider-Man: No Way Home was a heartbreaking one. After the memory of Peter Parker had been wiped from the world, the two happen to run into each other at Aunt May's grave.

RELATED: 10 Most Powerful Skrulls In Marvel Comics

Though Happy wouldn't know who Peter is, a Skrull could have been keeping tabs on Spider-Man and used this opportunity to get close to him in the hopes of replacing him as well. It would help to explain the coincidence of them happening to be at the cemetery at the same time.

Nakia

Nakia (Lupita Nyong'o) - Black Panther

When Nakia was introduced in Black Panther, she was content with living outside of Wakanda and helping people as a soldier. At the end of the movie, she does agree to stay with T'Challa, but unlike the other characters from Black Panther, she hasn't appeared in the MCU since then.

If Nakia was a Skrull at the end of Black Panther, it would help to explain her change of heart as well as why she didn't help her fellow Wakandans in other conflicts. It would also make sense that the Skrulls would want to make their way into the advanced society of Wakanda.

Sharon Carter

Sharon Carter Power Broker

Sharon Carter was shown to be a brave and heroic secondary character who was more than willing to fight for what she believed in even if it put her in danger. That is why many fans were surprised when she turned out to be the villainous Powerbroker in The Falcon and the Winter Soldier.

While the show gave the explanation that she was abandoned as an outlaw after helping Steve Rogers in Captain America: Civil War. But it would make a lot more sense if that wasn't Sharon Carter at all. It would also be an interesting way of connecting the Disney+ shows.

NEXT: 10 Storylines The Secret Invasion Disney+ Series Can Have, According To Reddit