One of the first alien races to really be focused upon in the Marvel Universe, the Skrulls are incredibly dangerous no matter what form they take. Debuting back in the Silver Age of Comics, these shapeshifting green beings were introduced as enemies of Marvel's First Family, the Fantastic Four. Since then, they've been a staple of Marvel's cosmic corner of the universe, getting into intergalactic wars with rival alien groups and plotting secret invasions. It's the latter point that shows the Skrulls' greatest potential, however, which is of a decidedly more grounded scope.
The Skrulls have ample opportunity to disrupt Earth's society by way of subversion and masquerading as its leader. This is something that the TV show adaptation of Secret Invasion does, and it's a particularly poignant idea in modern society. In a world where deep fakes and conspiracies run rampant and seem to have grains of truth added to them by the day, the Skrulls would easily be able to thrive at throwing humanity's trust for itself into disarray. Here's how this concept fits right in line with the species' premise and how Marvel's use of the aliens has sadly gone in different directions.
The Skrulls Have Mostly Been Relegated to Cosmic Marvel Stories
Created by Stan Lee and Jack Kirby, the Skrulls debuted in Fantastic Four #2, with the issue dealing with one of their many planned invasions of the planet Earth. This would also be only one of several encounters between the species and the heroes, with the Skrulls becoming chief enemies of the team. In fact, the warrior Kl'rt (a.k.a. the Super-Skrull) would be genetically engineered to emulate the Fantastic Four's powers. Given that the team is the first major group in the Marvel Universe, it makes sense that their alien enemies would have ties to other characters, heroes and properties throughout the galaxy. The Skrulls would be engaged in all manner of cosmic conflicts, namely two Kree-Skrull wars and other incidents involving various races in the cosmos. Members of the species would even be present during the iconic X-Men storyline "The Dark Phoenix Saga," and they came to the same conclusion as everyone else pertaining to the Phoenix's immense threat level.
The Skrulls' ties to the X-Men would continue in further stories involving the villainous mutant Apocalypse, and it was revealed that a mutant/Skrull hybrid species also existed. Other major stories featuring the green fiends include the cosmic crossover Annihilation, with the Skrull Empire absolutely ravaged by fellow Fantastic Four enemy Annihilus. This would somewhat segue into the events of Secret Invasion, in which a group of Skrulls tried to make Earth their new home by impersonating well-known superheroes. Beyond this, however, the aliens' antics don't usually involve or affect the more every day, street level heroes of the Marvel Universe. This makes their threat into something on a grand scale and almost esoteric, particularly for fans who might eschew Marvel's cosmic offerings. The worst part of this is that the Skrulls fit perfectly into a particular niche in modern society, and it could turn them into a very real threat to the average Joe residing in the Marvel Universe.
The Skrulls as a Metaphor for Misinformation and Conspiracies
As mentioned, the Skrulls have remained a fairly cosmic threat for their decades of publication history. Nevertheless, their most interesting story is set right on Earth, and it's being showcased somewhat in the Marvel Cinematic Universe version of Secret Invasion. The television series changes the premise of the alien invasion somewhat by switching out imitated superheroes for the Skrulls instead taking the forms of the humans in power across Earth. This takes the comic book version of the story to new heights through its central theme of distrust. In the comics, the superhero community worried over whether some of their greatest champions were actually shapeshifting Skrulls in disguise. By utilizing this concept in another way, the Marvel Universe could force its every day citizens to ask the same question about elected officials.
This would play right into many modern conspiracies that proliferate the political landscape. For one, there's the belief among some that major government actors truly are "actors" in every sense of the word, with these politicians having outright body doubles used for various nefarious deeds. Thus, the presidents, prime ministers and other people in power seen on TV might not actually be the genuine article. This has only gotten worse in modern times due to the social media phenomenon of "deep fakes," in which video and audio footage is doctored to make it seem as if they're doing or saying things that are entirely uncharacteristic.
Likewise, another popular theory pertains to the existence of shapeshifting reptilian humanoid aliens, with these lizard invaders and their devious aims being popularized by several conspiracy theorists. This concept is the exact same as the Skrulls themselves, and the idea that the Marvel Universe's governments are run by amoral alien invaders would send a chill down the spine of even seasoned fans of superhero stories. The worst part would be that even the heroes might be powerless in the wake of such a revelation, as they wouldn't simply be able to punch a politician in the face on suspicion of their being a Skrull. The aliens even have their own religion, with one group seeing Earth as divinely theirs to conquer, echoing the real world manifest destiny mentality.
Going down this route with the Skrulls could make them into an even bigger threat, as they'd no longer be confined to the realms of an intergalactic empire in cosmic stories. They would now be a very real bogeyman for the everyday people of the Marvel Universe, becoming the perfect allegory for a modern, yet polarized society. This type of story would also be the perfect way to bridge the gap between Marvel's cosmic characters and more street-level, grounded concepts. All of a sudden, the biggest threat to human existence wouldn't be a giant planet-eating entity or a collection of incredible stones with infinite power. Instead, it would potentially be the heroes meant to protect citizens, the politicians meant to serve them, or even the people themselves.