The Skrulls have often been considered one of the most dangerous cosmic enemies in the Marvel Universe. However, the depiction of the Skrulls in Captain Marvel may have created a different trajectory for the alien race. Despite the Skrulls' Captain Marvel story arc, the Skrulls' Marvel Comics history is pretty well established, even if it is a bit questionable and difficult to follow.
After all, this is an alien race with billions of individuals, many of whom have interacted with Earth's Mightiest Heroes on more than one occasion. Depending on which Skrulls Marvel Comics you've read - if any - odds are you don't have the full scope of who these shapeshifting aliens truly are. Will their depiction change in the comics now that they've finally been seen on screen, or will the Skrulls from the books remain the villainous monsters who launched "Secret Invasion?"
This list should clear things up as to how the Skrulls have been depicted throughout their decades-long history in Marvel Comics, as well as their time on screen.
Warning: Captain Marvel spoilers ahead.
The Skrull race made their debut back in a Fantastic Four #2 issue called The Fantastic Four Meet the Skrulls from Outer Space! The issue kicked off with the Fantastic Four acting rather strangely. The Thing goes on a rampage against an oil platform off the coast of Texas, the Human Torch completely melts a statue the moment a small town unveils it, the Invisible Girl steals a priceless gem from a jewelry store, and Mister Fantastic takes out a power plant.
It turns out it was a group of alien imposters, the Skrulls, are actually behind the attacks. A small group of Skrulls arrived on Earth and emulated the Fantastic Four as part of their plan to carry out a full-scale invasion. Seeing that the FF might get in their way, they sought first to ruin their reputation while the real team was hanging out in a hunting lodge.
Eventually, the real FF is arrested, but they escape and draw out the invaders. The superheroes subdue the creatures and take their rocket to the Skrull mothership in orbit. They pose as the infiltrators and convince the Skrull commander that Earth is too dangerous to invade. When the group returns to Earth, the subterfuge of the Skrulls is revealed. Reed convinces the three remaining aliens to turn themselves into cows - and actually convinced them that they were cows.
Long before the Skrulls became a race of intergalactic travelers, they were a reptilian species devoid of complex abilities. They were altered by the Celestials, a race of ancient, immensely powerful aliens who had a hand in creating many of Marvel's sentient species.
There is little information as to why the Celestials took it upon themselves to tinker with the evolution of life on various worlds. They are some of the most mysterious beings in all the cosmos, but also some of the most powerful. They are incredibly difficult to destroy and are seemingly immortal.
Thanks to the Celestials' experimentation, the Skrulls evolved into a new race of creatures that diverged into three separate branches: the Prime, the Deviants, and the Eternals. The three species clashed as they tried to assert dominance over one another. The Deviants wound up on top, thanks to their shapeshifting abilities, and became the Skrull Empire.
During their rise, the Deviants wiped out all the Primes and Eternals, save for two. One Skrull Eternal named Kly'bn remained, as did one Prime Skull. Eventually, the leader of the Deviants, Sl'gur't, fell in love with Kly'bn, and they fell into lore as the original gods of the Skrull pantheon. The remaining Prime fled to Earth in the 20th century to become a member of the Underground Legion.
Long ago, before the Skrulls became a force in the universe bent on Galactic conquest, they were a much different race. The Skrulls started as a mercantile society centered around trade. They were initially willing to share what technological advances they had with other races they felt worthy of using it, and they remained free of conflict. Whenever they found a new race, they would change their appearance to match and fit in.
All was well with the Skrulls until they figured out how to do long-distance space travel. This discovery allowed them to leave their home galaxy and explore the Milky Way, which was full of intelligent species. As the Skrull Empire expanded to more than 50 worlds, they continued their free-trading ways.
Everything came to an end when they found the Kree on Hala, which ignited the Kree-Skrull War.