The Skrulls are coming, and they’re a threat unlike anything the Marvel Cinematic Universe has ever faced. As announced during the Marvel panel at San Diego Comic-Con, the iconic green-skinned, ridge-chinned extraterrestrials will finally make their way to the big screen as the villains in 2019’s Captain Marvel movie. Over the years they have gone from looking like Dobby the House Elf’s seasick cousins to ‘roided up Green Goblin cosplayers, but they have remained an essential part of the fabric of the Marvel Universe all the while. Why should you care about these little green men from outer space? Allow me to explain on today’s episode of The Dan Cave.

Created by Stan Lee and Jack Kirby, the Skrulls made their auspicious debut way back in 1962’s Fantastic Four #2. These humanoid alien invaders have made a lasting impact on the Marvel Universe, cutting an imposing figure with their pointed elfin ears, ridged jawlines, and beady red eyes. The war-like Skrull Empire has been a constant thorn in the side of everyone from the Fantastic Four to the Avengers and beyond thanks to their powerful shapeshifting abilities and their brutality in combat.

Hundreds of millions of years ago, the Skrull race emerged on the aptly named planet Skrullos in the Andromeda Galaxy. While they were still considered primitives on the evolutionary scale, a group of cosmic engineers known as the Celestials came across the Skrulls and began experimenting on them. Their physiological structure was manipulated so that the Skrull race split into three distinct groups—the Eternals, imbued with long life; the Deviants, capable of shapeshifting; and Normals, or “normies” as I like to call them, who became the ruling class for a long time until the Deviants (with their ability to mimic others and transmogrify themselves) eventually wiped out the other two races to become the last Skrulls standing.

In their very first comic book appearance, a detachment of Skrulls arrived on Earth in advance of their invasion fleet, which was assembled with the intention of conquering our pale blue dot. Once on our world, the Skrull advance squad transformed themselves into the Fantastic Four, since Marvel’s First Family was the only superhero group powerful enough to stop them. Unfortunately for the Skrulls, the Fantastic Four managed to trick the Skrull leaders aboard the invasion fleet that the Earth wasn’t worth conquering as it was too dangerous and too much work. To add insult to injury, Reed Richards, a.k.a. Mr. Fantastic, convinced the Skrulls remaining on Earth to disguise themselves by transforming into cows. Once they were in their new bovine forms, Richards hypnotized them into believing they were actual cows and put them out to pasture for the rest of their days.

Image: Marvel via Blogspot

The majority of Skrulls lived far, far away in the totalitarian monarchy’s massive intergalactic empire, which has suffered catastrophic losses over the years due to cosmic menaces like Galactus and the Annihilation Wave. At one point, their empire included a weird star system called the Kral system, which they converted into what was essentially an amusement park for the ultra-rich, complete with recreations of Prohibition-era New York City and a medieval Earth village. They also held intergalactic gladiatorial tournaments, and—wait, isn’t this basically the villain’s plot from Space Jam, but with less basketball?

Several elite Skrull agents have infiltrated the Earth over the years, wreaking havoc and forcing Earth’s superheroes to put aside their differences and stop the Skrulls’ nefarious plans. In one instance, the Skrull Paibok used another Skrull called Lyja to replace Alicia Masters, the Thing’s blind sculptor girlfriend, and had her seduce the Human Torch. Unfortunately for Paibok, Lyja’s love for the Human Torch burned too brightly and she betrayed her people, ultimately sacrificing herself to save Johnny.

Another powerful Skrull warrior known as Super-Skrull was specifically engineered to possess the powers of all four members of the Fantastic Four, and sent to Earth to take sweet, green revenge on the superhero team that dunked on his masters in the first place. His misadventures wound up getting Sue and Johnny Storm’s father killed, and he even went on to help Thanos in his quest to capture the Cosmic Cube. Yet time and time again, Super-Skrull would get his butt handed to him and be sent packing to the far reaches of space.

So how will the Skrulls play into the Marvel Cinematic Universe? While the Chitauri from the comic books are basically the Ultimates Universe version of the Skrulls, they will in fact be two separate, distinct races in the MCU. We know that the Skrulls will be the villains of the Brie Larson-starring Captain Marvel, and there’s a good chance that could be playing into a larger Kree-Skrull War storyline based on what happened in the comics. In the Kree-Skrull War, Earth’s Mightiest Heroes find themselves embroiled in an intergalactic conflict between the Skrulls and the Kree, which you may remember as the race of Ronan the Accuser from Guardians of the Galaxy. What better way to explain where Captain Marvel has been all these years than if she had been off-world, helping prevent an interstellar conflict from catching Earth in the crossfire?

Alternately, since Captain Marvel takes place in the 1990s, and Marvel is likely going to start phasing out some of its bigger name actors like Robert Downey Jr and Chris Evans, who after a decade of playing the same character are likely champing at the bit to move on to the next chapter in their careers, the House of Ideas could be teeing up for a movie adaptation of “Secret Invasion.” The fan favorite comic book storyline is basically a spandex-clad version of Invasion of the Body Snatchers, with a story about Skrull sleeper agents on Earth infiltrating organizations like S.H.I.E.L.D. and secretly replacing some of Earth’s most powerful heroes. Basically, the idea is that anyone could be a Skrull, and it was absolute paranoid chaos. Introducing the notion that any one of the heroes we know and love could really be a shapeshifting alien in disguise could let Marvel play fast and loose with its timeline, and really up the ante as we introduce new heroes into the fold and head into the second decade of Marvel’s unique brand of superhero cinema.

How do you hope to see the Skrulls integrated into the Marvel Cinematic Universe? Do you think we’re heading towards Secret Invasion? Let us know in the comments below.

Images: Marvel Comics

Sources: Marvel, Wikia, Comic Vine

Want to watch The Dan Cave before anyone else? Join Alpha and get early access.

Don’t miss a single episode of The Dan Cave! Subscribe to this playlist.

Tired of getting kicked out of restaurants for being topless? Buy a The Dan Cave t-shirt!

Dan Casey is the senior editor of Nerdist and the author of books about Star Wars and the Avengers. Follow him on Twitter (@DanCasey).