Secret Invasion: How Does Skrull Shapeshifting Work? What We Know From The Comics

Nick Fury (Samuel L. Jackson) is facing a new threat in his latest appearance in "Secret Invasion." While the Skrulls may not be as big of a threat as Thanos (Josh Brolin), their abilities and powers create a paranoid dynamic that can isolate any hero (or enemy, depending on the perspective). The ability to shapeshift allows them to imitate anyone on Earth and makes them incredibly difficult to track. Of course, in the series, it seems to be simply a part of their physiology, but in the comics, it is the result of a scientific test done millions of years ago.

The scientific explanation of the power to alter a Skrull's own appearance, and in some cases complete physical make-up, comes down to their bodies being made up of unstable molecules that can be realigned to allow them to imitate what they see, even changing their respiratory systems to fit other planetary atmospheres. This makes them able to adapt to any planet, environment, or crowd. 

Shapeshifting makes them a formidable enemy that could surround you completely, and you would never even know it. In Fury's world of keeping secrets and working in the shadows, this talent makes them even more dangerous and causes the veteran superspy to isolate himself. As we find out in the first episode of the series, when you are going toe-to-toe with the Skrulls, nobody is more dangerous than your best friend.

The Skrulls are one of the oldest populations in existence. Their close relation to multiple species present on Earth makes them particularly intriguing, owning traits common with both humans and reptiles. Millions of years ago, the still primitive people were visited by the Celestials, the beings responsible for both the Eternals and the Deviants.

Like seemingly every civilization in Marvel Comics, Skrulls were a target of the meddling hands of the Celestials. When they came to the planet of mostly peaceful and primitive Skrullos millions of years ago, they began experimenting on the Skrulls and created three different groups. The first were the unaltered Skrulls, called Latents, who had no powers but evolved similarly to humans. The Eternal Skrulls were given powers meant to make a difference on the planet. And then, finally, the Deviant Skrulls were gifted the ability to shapeshift using unstable molecules that can rearrange themselves to mimic anything solid.

After a civil war on Skrullos, the Deviant Skrulls wiped out everyone else and became the last known group of the population, meaning that all the remaining Skrulls that we see in the MCU today are likely descendants of Deviants. Their shape-shifting abilities assisted them in becoming more warlike and led them down a path that would ultimately destroy their home planet. They look to do something similar with Earth as the villains in "Secret Invasion" seem to be headed down the path of creating Super Skrulls, Deviant Skrulls with the superpowers of the Eternal Skrulls. 

The Skrulls aren't the only beings in the Marvel Cinematic Universe that can shapeshift. While many characters can do it in their own way, there are some differences in how they do it. Andrew Ceco of Sideshow breaks them down in a handy guide with some fun classifications. Loki (Tom Hiddleston) uses magic to shapeshift, dubbed "omnimorphing." Bruce Banner (Mark Ruffalo) "trans-morphs" into the Hulk. And Ant-Man (Paul Rudd) can shrink or expand in a process called "micro/megamorphing."

Characters that we haven't seen yet, but could soon, that can shapeshift into other forms include Mr. Fantastic, who can alter his body by stretching or expanding is called "polymorphing," and Mystique, who can only imitate other humans in a process called "metamorphing." These skills all use different scientific processes to accomplish the goal of altering everything from their appearance to the complete chemical makeup of their bodies. Skrulls, while only shifting into other humans so far, can do much more in the comics, as they can turn into anything that is solid—sizes ranging from the Hulk to Ant-Man.

While there isn't a lot of clear information in the comics, which are also a bit inconsistent at times, it seems that the Skrulls are a terrifying combination of all the shapeshifting talents, able to alter their unstable molecules to imitate anything or anyone. Add to that the abilities of the Super Skrulls, and Nick Fury has his hands full.