The Marvel Universe is huge, spanning galaxies, realities, and dimensions. While many of the adventures that the Marvel characters partake in occur on Earth, there are decades of adventures that have pulled the heroes into the far reaches of outer space, into different dimensions, and beyond. As such, there are dozens and dozens of species of alien creatures, cosmic entities, and omnipotent beings that live throughout the various comic storylines throughout Marvel’s long and storied history.

Ranging from species that died out long ago to those that still travel through space seeking to conquer new planets, we’ve compiled this list of some of the most powerful alien species that Marvel has shown us. We looked for species that would be familiar to fans of the MCU, as well as the most influential alien species in the comic books. Some of these creatures are truly unstoppable, others have squandered potential. But each is interesting and fascinating in their own way. None of these species is exactly the same- even the Chitauri and Skrulls, who were originally alternate universe versions of each other. For more details on the species that gave us Venom to the biology of Thor: Ragnarok fan-favorite character Korg, check out our full list below!

20 CENTAURIANS

The Centaurians are a species with a lot of potential for power, but unfortunately were slaughtered by a more powerful species. The Centaurians are from the planet Centauri V and they have blue skin and a large red dorsal fin on the top of their heads, giving them an overall height of around seven feet. They have some psionic abilities, able to use soundwaves to manipulate the arrows they shoot, but their technology is quite primitive, seeing as their primary weapons are bows and arrows.

The best-known Centaurian is Yondu Udonta, a member of the original Guardians of the Galaxy in the comics and is believed to be the last of his kind.

The rest were destroyed by the Badoon. Yondu makes it his mission to fight the Badoon, forming the original Guardians with Charlie-27 and Martinex. In the MCU, Yondu Udonta is a bit different from the comics. His dorsal fin is not part of his biology, but is instead an object that allows him to control his arrow, which is far more powerful than the primitive arrows the Centaurians use in the comics. He is the MCU’s version of the Earth-616 universe’s Yondu, who is the ancestor of the Yondu from the original Guardians of the Galaxy.

19 KLYNTAR

The Klyntar (most often referred to as the Symbiotes) originated from a planet called Klyntar in the Andromeda Galaxy. The Klyntar are a mostly benevolent race, seeking to help others by bonding with the best hosts they can find -- if bonded to an evil host, the symbiote can become corrupted and become a parasite. The parasitic symbiotes are the more space-faring of the two, conquering planets and feeding off of the hormones of their hosts.

The best-known symbiote in the MCU is Venom, who was the first symbiote brought to Earth. He bonded to Spider-Man, but was rejected by the young hero for being too aggressive. The rejected Venom bonded to several hosts afterwards, becoming more or less altruistic depending on the person he was bonded to. Venom had several spawns, including Carnage. Because most of the symbiotes on Earth are spawn of either Venom or Carnage, the symbiotes have taken on a mostly villainous role, but the species itself isn’t inherently evil. They have several abilities, mostly enhancing the abilities of their hosts. Superior strength, speed, and healing are some of the perks for the host. The symbiote itself, in a liquid form, can infiltrate nearly anything for the sake of gathering intelligence or disabling technology. It can also change appearances and even make the host appear invisible, but without a host, the Klyntar symbiotes aren’t much of a threat.

18 KRONANS

The Kronans are a race of giant rock-beings that resemble stone humans. Being made of inorganic stone, they are genderless. To reproduce, the Kronans join hands and the hands melt together, and when the two Kronans separate, an infant Kronan is left behind. Their home planet is Ria, a planet near the sun Krona in the Milky Way galaxy, though they are sometimes referred to as the “Stone Men of Saturn".

The best-known Kronan is Korg, Hulk’s warbound ally from the "Planet Hulk" storyline.

He helps Hulk fight against the Red King, escaping from the gladiator arena and leading an uprising to return control of the planet to its people. We don’t see many Kronans in the MCU, but there have been two: in the early moments of Thor: The Dark World, Thor is seen taking down a Kronan with one swing of his hammer. The next Kronan we meet is Korg, who allies himself with Thor and the Hulk in Thor: Ragnarok, which served as the MCU’s adaptation of that "Planet Hulk" storyline. As a species the Kronans are extremely strong and resilient. Though the stone giants can be broken and defeated, it takes someone very powerful to do so.

17 XANDARIANS

Xandar is the home of the Nova Corps, a group that protects the galaxy from cosmic threats. The Xandarians are a humanoid species, very similar to the humans of Earth, but they are technologically advanced, with greater exposure to other civilizations throughout the universe. The planet has been attacked several times, nearly being destroyed by the Skrulls. It is later actually destroyed by Nebula, and then once again by Annihilus.

The Nova Corps protects the peaceful Xandarians and are one of the most powerful fighting forces in the galaxy. They are powered by the Nova Force, which is created by the Xandarian Worldmind, a group of living supercomputers on Xandar. This Nova Force gives members of the Nova Corps super strength, the ability to fly, energy abilities, and many other powers. In the MCU, Xandar appears in Guardians of the Galaxy. Ronan the Accuser uses the Power Stone to attack the planet, which he holds responsible for the deaths of his relatives who died in battle with the Xandarians. For Thanos to get the Power Stone, he had to attack Xandar, though it is unknown what state he left it in when he was finished. Hopefully we’ll find out in Guardians of the Galaxy Vol. 3.

16 THE BROOD

The Brood are an evolved insectoid alien species that shares a sort of hive mind mentality, working for the sake of their Queen. They are parasitic, moving from planet to planet destroying anything in their way and using up resources. They reproduce by infesting host species with their eggs. Their appearance and behavior is sometimes compared to that of the xenomorphs from the Alien movie franchise. They have elongated heads, sharp teeth, and wings.

Their insectoid legs are also razor sharp and they also have stingers that are capable of poisoning their victims.

As mentioned before, the Brood functions as a hive mind, with a hierarchy starting with the Brood Empress, who is the supreme leader of the species. The Brood Empress has several Brood Queens, whose job it is to carry out the Empress’s will. The Empress also has several Firstborn spawn, the most pure of the species, who are her trusted guardians. The vast majority of the Brood, though, are broodlings -- soldiers that exist only to fulfill the wishes of the Brood Queens and Brood Empress. Despite the sadistic pleasure the Brood gets from the terror they inflict, they do not turn on those that are higher on the social order. However, Brood Queens have no allegiance to one another. Still, the powerful telepathy that ties the Brood together makes them formidable opponents when they are united in one cause.

15 SAKAARANS

Sakaar is the planet on which much of the "Planet Hulk" storyline takes place. The people of the planet are divided into two distinct races: the Imperials and the Shadow People (or the Oldstrong). The pink-skinned Imperials are the ruling race on the plant, led by the Red King. The Oldstrong, though not originally from Sakaar, mostly reside on Sakaar.

The Imperials made an agreement with the Shadow People to work together to defeat the Spikes and in honoring this agreement, however, the Red King came to power and began to rule unfairly, imprisoning and enslaving whoever he saw fit. Several of the Oldstrong became guardians of the Red King, including Caiera, who carried the Red King’s daughter, and Elohim the Shamed, who thought he was the savior that had been prophesied to save the world. Both of these Oldstrong ultimately work with Hulk to overthrow the Red King. Elohim was one of Hulk’s allies from the beginning, recognizing Hulk to be the true savior of the prophecy. Caiera only joined when she realized that the Red King had weaponized the spores to use against his own subjects. The Imperials have technology that allows the to weaken and control their slaves. The Oldstrong are connected to the Old Power, a manufactured version of the Power Cosmic. In Thor: Ragnarok, the planet Sakaar appears, but the Oldstrong and Imperials are nowhere to be seen.

14 BADOON

The Badoon are a reptilian species that is older than either the Kree or the Skrull, but are an extremely segregated species, resulting in two distinct societies, separated by gender. The two societies --  the Sisterhood of Badoon and Brotherhood of Badoon -- are ruled separately by independent rulers and live on different planets. The female Badoon lost a long-running gender war within the species, becoming enslaved on the species’ home planet. The males developed technology and eventually left the planet, returning only to mate with the females, who, unlike their warlike male counterparts, are pacifists.

The males have partnered with several species in the past, including the Kree and the Brood.

They’ve also attempted to takeover Earth on several occasions. Fortunately, they were driven off by the likes of Silver Surfer and Namor. They’ve also faced the Fantastic Four and the X-Men, both groups that find themselves facing interstellar threats from time to time. The Badoon don’t have any particular special abilities, like increased strength or flight, but their technology allows for interplanetary travel at speeds greater than light, and they have weapons like a particle blaster, as well as a personal cloaking device. Some Badoon also wear a self-destructing devise that can kill enemies if a Badoon warrior finds that they are defeated.

13 THE SPIKES

The spikes are not seen much in the Marvel Universe, but their presence in the "Planet Hulk" storyline showcases just how powerful they are. The species is made of intelligent spores who feed on the energy of dying stars. Prior to the events of "Planet Hulk", the spores crashed on Sakaar. Cut off from their typical food source, the spores went insane and began feeding on any organic material they could find. When the spores attack a living body, that body begins to mutate with spikes protruding out of it. The body is taken over by the consciousness of the spores, which make the body seek out other bodies for the spores to feed off of.

The spikes were eventually stopped by the ruler of Sakaar, who sent them away from the planet’s surface in a spaceship. However, instead of being blasted back to space, they were sent to one of Sakaar’s moons. The spikes are eventually harnessed by the Red King of Sakaar to fight Hulk and his allies, a decision which leads to the destruction and death of many innocent members of the Sakaaran society, but Hulk is able to fight off the spikes and make a deal with them -- they even feed off of his extra energy for a time. After the defeat of the Red King, the Hulk sends the Spikes to space to continue on their previous path to a dying star, where they could continue to live without needing to feed on organic matter.

12 TECHNARCHY

The Technarchy are a biotechnic species that can take on any shape, form, and appearance. Their typical appearance has a gold and black color scheme. They are usually hostile, destroying the planets on which the organisms have been exposed to the transmode virus. The most prominent members of the Technarchy are Magus and Warlock, with the former being the ruler of the Technarchy, which is governed by a monarchy. Tradition in the culture is that the leader must engage his children in combat to determine who has the right to rule the species. Warlock, with the mutation of kindness, a quality that is absent from the other members of his species, fled to Earth to avoid fighting his father. Magus eventually attacked Earth in his search for Warlock, but Warlock had teamed up with the X-Men by that point.

Magus created the transmode virus in an attempt to strick at Warlock and the X-Men, but the virus spread throughout the galaxy, turning its victims into members of the Phalanx.

Warlock became a hybrid of Phalanx, human, mutant, and Technarchy. Magus himself was eventually infected by a mutated strain of the transmode virus. When the Technarchy’s planet was last seen, it was barren and desolate, with the Technarchy apparently extinct.

11 PHALANX

The Phalanx is a name given to any species that has been infected by the Technarchy’s transmode virus. Those that are infected become assimilated into the Phalanx hive-mind, and their biology is converted to a sort of cybernetic biotechnology. Once a living being has been converted to a member of the Phalanx, they lose their individuality, operating according to genetic programming and the hive-mind. The Phalanx are able to shapeshift and teleport, infiltrating the societies using these abilities and gaining new members by spreading the virus through physical contact. Once they gain enough members, they begin to construct a Babel Spire to summon the Technarchy. Unfortunately for all involved, the Technarchy view the Phalanx as mutations that need to be destroyed, so the Technarchy targets the planets on which Babel Spires have been built. Their power is in their ability to stealthily infect a society, but their goals ultimately lead to their own destruction.

The Phalanx have most often come into conflict with the X-Men. Fortunately the mutant X-Gene provides the X-Men with an immunity to the transmode virus that creates Phalanx. The X-Men have also teamed up with Phalanx that have been separated from the hive-mind. Mr. Sinister used the Phalanx to learn how to clone himself and link telepathically with each of his copies, while Cable used a Phalanx fetus to heal himself, managing to overpower the mental abilities of the fetus and avoiding being assimilated into the hive-mind.

10 CHITAURI

The Chitauri were originally the Ultimate Universe’s version of the Skrulls. They are a shapeshifting race that has attempted to conquer Earth on several occasions, including during World War II. They use their shapeshifting abilities to operate within the society of the planets that they take over, influencing events to lead to the ultimate destruction of the planet’s social order and the takeover by the Chitauri. The Chitauri believe they are performing the functions of a universal immunity system, purging undesirable traits from the living creatures in the universe.

Though their original form in the Ultimate Universe was similar to the Skrulls, the Earth-616 Chitauri are quite different.

They resemble much simpler-minded animalistic creatures, following and serving a Queen in a sort of hive-mind. The Chitauri were used by Loki in The Avengers to attack New York City in an attempt to take over Earth. They have a sort of bio-mechanical body type, superior strength and armor, and technology that far surpasses that of Earth. They have massive living troop transport ships called Leviathans, and though they lose to the Avengers, they manage to cause a lot of damage before going down. This invasion influences much of the MCU afterwards, leading to the events of Agents of S.H.I.E.L.D. and being referenced often in Jessica Jones, Luke Cage, and Daredevil. Their technology is also used by Vulture in Spider-Man: Homecoming.

9 THE SOVEREIGN

The Sovereign are the gold-skinned species that exists in the MCU and is seen primarily in Guardians of the Galaxy Vol. 2. They are very highly evolved to the point of the society and culture essentially functioning as a utopia. Every member of the Sovereign is designed and born to fill a specific needed role. They are an easily offended and highly conceited race, but they have very effective genetic engineering technology and drone ships that can be piloted and controlled from interplanetary distances. The leader of the Sovereign is called Ayesha, and it is her defeat by the Guardians of the Galaxy that leads her to create Adam Warlock, an extremely important character to the Marvel Universe. As of yet, he hasn’t been officially introduced, and rumor has it we won’t see him until Guardians of the Galaxy Vol. 3.

The Sovereign most closely resemble the Marvel comic group known as the Enclave -- though not in appearance, but in action. The Enclave were a group of scientists who genetically engineered Adam Warlock (or Him, as they referred to their creation). They also created Ayesha (also called Kismet or Her). The Sovereign of the MCU, though, clearly have the technology necessary to create a perfect society; the kind of intelligence and discipline required to maintain it places the Sovereign high on this list.

8 SHI’AR

The Shi’ar are the third major alien empire in the Marvel Universe. While humans evolved from primates and Skrull evolved from reptilians, the Shi’ar evolved from birds, and thus their biology is heavy avian. They have hollow bones and feathers instead of hair. They also reproduce through the use of eggs and incubation chambers. For the most part, these are the major similarities with their birdlike ancestors, but a few genetic anomalies exist that have the ability to fly.

However, even those that can’t fly are able to lift heavy weight on the Earth and have greater stamina than humans.

The Shi’ar have worked closely with the X-Men in the past; Lilandra, the Empress of the Shi’ar, has a strong romantic bond with Charles Xavier, and the two groups have helped each other at many points in the past. The Shi’ar have given the X-Men various kinds of technology, like the holograms used in the Danger Room and the cloaking technology used in the X-Men’s Blackbird jet. One major difference between Shi’ar and most other intelligent species is an inability to dream. This has led to a cultural distaste for art and creativity. Those Shi’ar who have a penchant for the creative are deemed insane, so they try to repress their creative instincts.

7 KREE

The Kree are among the most prominent alien species in the Marvel Universe, appearing to modern humankind first during the events of the "Kree-Skrull War", when the two rival species fought for control of the planet. The Kree are known primarily for being a race of warlike conquerors, their empire stretching across thousands of planets. At some point in the past, the Kree’s evolutionary process stopped and they began to experiment with ways to kickstart evolution in their own species and others. As part of these experiments, they visited Earth and performed the experiments that led to the creation of the Inhumans. There are several other Kree hybrids, like Captain Marvel, and much of their conquering helps to serve their experimental attempts at continuing their evolution and crossbreeding.

The Kree are stronger than humans on Earth due to Earth’s lower gravity, but they are unable to breath while on the planet. Typically, the most powerful members of the Kree are blue and these blue Kree are considered the “pure” race on the planet. Though these blue Kree are the minority, they are a powerful minority, controlling most of the planet. Notable members of the Kree for fans of the MCU include Ronan the Accuser and Korath the Pursuer, who were villains in Guardians of the Galaxy. The Kree also play a fairly large role in the Agents of S.H.I.E.L.D. TV show.

6 SKRULLS

The Skrulls were experimented on by the Celestials millennia ago, creating three branches of Skrull lineage: the Eternal, the Deviant, and the Prime. The Deviant race, gifted with the ability to change their shape, managed to wipe out all of the other races with the exception of one representative of each. These deviants later split into two races, as well, with one branch known as the Dire Wraiths.

The Skrulls have a long history in the Marvel comics, going back decades to the "Kree-Skrull War".

They have often fought against the Fantastic Four -- one of the main Skrull characters is known as Super-Skrull, and is equipped with the abilities of each of the Fantastic Four. They have also invaded Earth during an event known as "Secret Invasion", which saw the identities of several prominent Marvel heroes taken over by Skrull imposters. With green skin and pointy ears, these reptilian aliens would be easy to spot if not for their shape-shifting abilities. However, they have yet to make an appearance in the MCU. Rumor has it that they will appear in the upcoming Captain Marvel movie, but up to this point, they have been unseen -- mostly due to the character rights being held by Fox.

5 ASGARDIANS

The Asgardians exist on a different astral plane, depending on which universe we are considering -- in the MCU, Asgard seems to be treated as a different planet or universe entirely. In any case, the Asgardians are the characters in the Marvel Universe that are based on the gods of Norse mythology. This includes Thor, Odin, Baldur, and many more. Each of the Asgardian characters is the god of some concept or thing, taking on the characteristics and qualities associated. For example, Thor, the god of thunder, is able to manipulate thunder and harness its energy. Loki, the god of mischief, is able to create illusions to deceive people.

The Asgardians watch over the Nine Realms and are extremely powerful. They fought millennia ago for control, ultimately coming to terms with the leaders of all of the realms. Though human in appearance, the Asgardians are all super strong and are capable of magical feats. As the guardians of the Nine Realms, they are nearly invulnerable and are all very formidable combatants. In the MCU, Thor has proven to be one of the most powerful beings in the universe, though there are several beings, like Thanos, who are more powerful. Still, the Asgardians are a force to be reckoned with.

4 WATCHERS

One of the oldest species in the universe, the Watchers are tasked with doing just as their name implies: watching and observing the major events that occur throughout the history of the multiverse to compile a database of all knowledge. They vowed to never interfere in a species by providing knowledge, because they had previously provided technology to a race that was not ready to use such technology -- the race ultimately destroyed themselves.

Despite this policy, however, Uatu the Watcher has interfered in catastrophic events on several occasions, helping the heroes of Earth defeat such threats as Molecule Man and Galactus.

Uatu’s pattern of interference eventually catches up with him, and he is banished from the Watchers for assisting the Fantastic Four in their fight against the renegade Watcher Aron, who is Uatu’s nephew. It also turns out that Uatu’s father is the Watcher who gave nuclear technology to the race that destroy itself. This tendency to interfere, therefore, is a trait that Uatu clearly gets from his father. He spends his time searching through the multiverse, hoping to find one universe where his father’s choice to impart this knowledge was a good decision. The Watchers can do just about anything they want as nearly limitless cosmic beings. But they simply choose not to.

3 ELDERS

The Elders are a collective of species, rather than an individual species itself. They are made up of the last members of various ancient species from throughout the universe, and are therefore some of the oldest and most powerful beings in the universe. They are essentially immortal, and over time have become associated with their various passions and hobbies. For example, there is the Collector, who collects samples of rare and interesting specimens throughout the universe. The Grandmaster creates cosmic games, pitting heroes and villains against each other. Ego the Living Planet is another Elder in the comic universe (though he is a Celestial in the MCU).

The Elders each wield the Power Primordial, which is energy that is left over from the original big bang that started the universe. However, not every Elder uses the power actively. The Power Primordial is nearly limitless in its capabilities, enabling healing, super strength and speed, teleportation, and more. The Elders are mostly benevolent, and those that do rope the heroes of Earth into dangerous situations are rarely doing so for any truly evil intentions. As beings that are older than most of the galaxies, they simply have little regard for the lives of mortals.

2 CELESTIALS

The Celestials are some of the oldest and most powerful beings in the Marvel Universe. They were created by the children of the Firmament -- the sentient first universe. The Firmament had developed the Aspirants to serve him, but several rebelled, choosing to create beings that could eventually evolve to be better than the established order. These beings were the Celestials.

A war broke out with the Aspirants seeking to kill the rebels and the Celestials, but the Celestials managed to emerge victorious.

The Firmament and Aspirants fled outside of Reality, a new sentient cosmic being called Eternity was created, and because Eternity was comprised of several realities, the multiverse was established.Within the new realities, the Celestials worked to develop the native species of planets, creating three distinct branches of the species’ genetic lineage: the Eternals, the Deviants, and a normal branch that may or may not be modified in minor ways to influence evolution in the long term. On Earth, these genetic experiments on our ancestors are the reason for the X-gene mutations and other heroes having powers unlocked by extreme disasters. Those familiar with the MCU have seen several Celestials: the space port known as Knowhere in Guaridans of the Galaxy is within the decapitated head of a Celestial. In the same movie, the Collector shows the Guardians an image of a Celestial named Eson the Searcher using an infinity stone to attack the natives of a planet.

1 BEYONDERS

The Beyonders have never been observed by anyone in the universe (even the Watchers), because they exist outside of our dimension. Thus, they need to act on Earth through the use of controlled agents. They first took an interest in Earth because of the nature of evolution, and created the Savage Land as a way to observe and study the concept. They are powerful enough to collect planets for their study, as well. The High Evolutionary is one of the first beings to witness the scope of the power of the Beyonders, finding himself in their museum of planets. He said that his mind snapped at the realization of how insignificant he was in the comparison to the Beyonders.

As part of their studies, the Beyonders once killed all of the Celestials alongside every cosmic and abstract entity, like Death and Infinity. This is all for the sake of completing an experiment in which all life in the multiverse is destroyed. The Beyonders create a character named Molecule Man in each reality, who is actually a living universe-destroying bomb. As beings that have killed the Celestials, they are among the most powerful beings in Marvel history, but they are not invincible; their own bombs were used against them and managed to destroy them.