As the Marvel Cinematic Universe has continued to expand, so too has its cast of characters from all corners of the galaxy. The introduction of the cosmic corners of the MCU began in earnest. First, there was the introduction of Asgard and Thor. Then, there was the Cosmic Cube, which threw Red Skull across the galaxy to a distant planet (a fact we wouldn't learn until seven years later). After that, the Avengers teamed up and fought the Chitauri, an almost unstoppable alien invading force. Finally, at the very end of phase one, audiences were given their first look at who would become the greatest threat in the MCU, and ultimately the glue that would bind Earth and the rest of the galaxy together: Thanos.
Since Phase One, the MCU has introduced plenty of other alien characters to the story, many of them possessing great power and abilities. They have often proved to be valuable allies to the heroes of Earth, as well as worthy adversaries that presented an uphill challenge. Avengers: Infinity War finally drew both the Earthly realm as well as the cosmic realm into the same story. Heroes from Earth were faced with the almost insurmountable task of fighting an enemy that seemed to possess powers beyond their understanding. Although they ultimately were unable to stop the outcome Thanos was working toward, audiences were given a hint that the voyage into the MCU's cosmic world had only begun, and with the release of Captain Marvel next year, there will be plenty more answers and insight into just what the MCU has in store. These are the 25 most powerful aliens in the MCU.
25 THE CHITAURI
The Chitauri made their first appearance in the MCU fighting against the newly formed super team in The Avengers. The battle of New York would go on to influence storylines throughout the MCU, and still stands as a defining factor in many of the MCU stories.
The Chitauri were a formidable foe for the Avengers, displaying great strength and technological prowess. Their powerful technology was later used by Adrian Toomes to create weapons in Spider-Man: Homecoming. However, due to their hivemind, they were defeated when Tony Stark destroyed their mothership.
24 THE GRANDMASTER
The Grandmaster (played with laid-back eccentricity by Jeff Goldblum) is the (former) ruler of Sakaar and the overseer of the contest of champions. Though he rules over Sakaar with an iron fist, he uses a gentle touch with his people, and uses the contests he puts on to keep them complacent.
The Grandmaster tells Thor that he has been on Sakaar for a long time, claiming that on any other planet he would be "millions of years old." His charm (and probably also his possession of a melting stick) allow him to stay in power (for a while, anyway).
23 THE COLLECTOR
Taneleer Tivan, also known as the Collector (played by Benicio Del Toro) is another ancient being, similar to the Grandmaster. In fact, as revealed at the Thor: Ragnarok panel at San Diego Comic-Con, the two are in fact brothers (at least in terms of both being Elders).
The Collector is shown to have a higher durability than an average being, when he is able to stand up to the explosion caused by the Power Stone. He is also, like the Grandmaster, an ancient being who is almost as old as the universe itself.
22 AYESHA (THE SOVEREIGN)
Ayesha (played by Elizabeth Debicki) is introduced as a secondary antagonist for the Guardians in Guardians of the Galaxy Vol. 2. She is the high priestess of the Sovereign, a golden skinned race of aliens who have genetically perfected their race.
Ayesha considers other alien species to be beneath her, only showing interest in Peter Quill (most likely due to his familial connections to the Celestials). She is extremely intelligent and ruthless in hunting down the guardians after they steal the Sovereign's anulax batteries.
21 MANTIS
Mantis (played by Pom Klementieff) is introduced as Ego's adopted child. She is a powerful empath who can sense what other beings are feeling upon touching them. She can also use this power to manipulate emotions. Mantis forms a bond with Drax through sensing his emotions.
When the Guardians first meet Mantis, she tells them that she mostly uses her powers to help Ego sleep, but aside from her empathy and empathic manipulation, she has also demonstrated a level of durability and agility beyond that of a human.
20 YONDU
Michael Rooker plays Yondu in the Guardians of the Galaxy films as a tough, weathered, and experienced ravager. Yondu is an experienced pilot and fighter, as well as a skilled thief and capable leader of the Ravagers.
Yondu's real power, though, lies in his control of the Yaka arrow. This ability is first demonstrated in Guardians of the Galaxy when he uses the arrow to easily take out an entire group of Sakaarans. In Vol 2, Yondu uses the arrow once again to dispatch an entire crew of Ravager mutineers.
19 KORATH
Korath the Pursuer (played by Djimon Hounsou) is a Kree mercenary and right hand man to Ronan the Accuser. He is a skilled soldier and marksman. He also possess a higher level of strength, durability, and agility due to his Kree heritage and training from Thanos.
Though Korath was defeated by Drax the Destroyer in the battle of Xandar, he will be seen again in the MCU when his origins as part of the Star-Force are revealed in Captain Marvel. Another character that will have their backstory revealed in the upcoming film is the Accuser himself, Ronan.
18 RONAN THE ACCUSER
Introduced first in Guardians of the Galaxy, Ronan the Accuser (played by Lee Pace) is Kree fanatic who craves power and wishes to destroy Xandar. Like other members of his race, Ronan possesses superhuman levels of strength and durability.
Ronan's strength also far surpasses that of the average Kree, likely due to his status as an Accuser (an elite group within the Kree army). This is demonstrated when he fights the Guardians and when he is able to handle the Power Stone without being torn apart.
17 CORVUS GLAIVE
Corvus Glaive (played by Michael James Shaw) is part of the Black Order and a child of Thanos. He is a skilled fighter and a ruthlessly loyal soldier who will serve Thanos at any cost.
Corvus Glaive has enhanced strength, agility, and durability in a fight, He is also an incredibly skilled warrior, using his namesake glaive as his main weapon. He is even able to take down Vision and Scarlet Witch before ultimately being defeated in the battle of Wakanda.
16 PROXIMA MIDNIGHT
Proxima Midnight (played by Carrie Coon) is another member of the Black Order. Like her husband, Corvus Glaive, she is a skilled fighter and soldier who is able to take on multiple assailants at a time. She is exceptionally skilled with weapons, including swords and her signature spear.
Proxima Midnight is a threatening presence, and shows little to no fear when fighting against the Avengers. Although she is ultimately defeated (along with the rest of the Black Order), she does not make it easy.
15 EITRI
Eitri (played by Peter Dinklage) makes his first appearance in Infinity War, where it is revealed that the Dwarf King is the last of the dwarves left on Nidavellir. Far from what would be expected, the Dwarves are a giant race, larger than humans or Asgardians.
Eitri demonstrates that due to his physiology, he possesses superhuman strength. He also ages differently than other beings, stating that he is thousands of years old. His engineering prowess and strength allowed him to forge Mjolnir in the past and to create Stormbreaker for Thor in Infinity War.
14 GROOT
Everybody knows Groot (voiced by Vin Diesel) by now, mostly because he keeps telling people that's who he is. Most people are also aware of Groot's strength and abilities. Groot, being a flora colossus, is a tree like being with the ability to grow his appendages, create plant life, and to spawn new versions of himself from a single piece.
Though he is a gentle soul, Groot has shown that he is willing to use his strength to fight for what he cares about. Even as a baby, Groot is able to utilize his skills effectively in fighting villains.
13 LOKI
Loki (played with villainous verve by Tom Hiddleston) is one of the mainstays of the MCU, showing up in two Avengers films, as well as all three Thor films. While not as outwardly powerful as his adoptive brother, Thor, Loki has demonstrated skill and prowess in manipulation and trickery.
In The Avengers, Loki used his power (in conjunction with the mind stone) to manipulate the team into turning on one another. He was also able to convince the Chitauri to fight for him in an attempt to conquer Earth. He has been shown to ably switch sides when needed, and is also a master of illusion.
12 CULL OBSIDIAN
Cull Obsidian (played by Terry Notary) is the largest and strongest member of the Black Order. He proves to be a formidable foe against Earth's Mightiest Heroes, easily overpowering almost every attack that is thrown against him. Along with his size, Cull Obsidian is also a skilled combatant.
Cull Obsidian demonstrates that he is even stronger than the Hulk when he easily overpowers the Hulkbuster armor and tears its arm off. He is only defeated when that same arm carries him into the Wakandan forcefield.
11 DRAX
Drax the Destroyer (played by Dave Bautista) quickly became one of the most popular characters in the MCU due to his fighting skill and just how funny he is. However, just because Drax enjoys a good laugh, doesn't mean he isn't serious about fighting.
On numerous occasions, Drax shows that he is more than willing to throw himself into the fight. Drax's skill with bladed weapons is enviable, and his regenerative factor gives him an edge by healing him faster than most other species. He also possess superhuman durability and agility in battle (though the still can't make himself invisible).
10 NEBULA
Nebula (Karen Gillan) is a technologically augmented member of the Kree race who is also a daughter of Thanos. She has shown that she has incredible strength and agility. She is also a skilled fighter who can heal herself using her robotic augmentations.
Nebula possesses these technological parts because every time she lost a battle with her sister, Gamora, she was enhanced further by Thanos. This treatment from her "father" also caused her to hold a massive grudge against Gamora. She wished to prove to Thanos that she was his strongest child.
9 GAMORA
Although Gamora (Zoe Saldana) started out serving Thanos, she eventually turned against him and joined the Guardians of the Galaxy. She has been shown to have immense strength, easily picking up a spaceship's gun and using it against Nebula.
Gamora is also an incredibly skilled fighter with a number of weapons, including blades and firearms. She also has incredible vision and endurance, easily surviving the time she spent in space without a spacesuit. These powers are also due to augmentations given to her by Thanos, though she required far fewer than Nebula.
8 EBONY MAW
Ebony Maw is by far the most devoted acolyte in the cult of Thanos, and easily the most powerful member of the Black Order. While he does not fight like the other three, he possess a superior intellect and telekinetic abilities that allow him to easily overpower and get ahold of Doctor Strange.
What might be the most frightening aspect of Ebony Maw, however, is his complete and utter devotion to what Thanos is trying to achieve. He is essentially preaching the word of the mad titan, telling the world that they will be much happier in the new world.
7 HEIMDALL
Heimdall (played by Idris Elba) is the all-seeing, all-hearing keeper of the Bifrost Bridge in Asgard. Heimdall is a particularly powerful Asgardian, possibly even more so than Odin. However, he is sworn to serve the king. That being said, he has used his powers to save Asgard in the past.
Like other Asgardians, Heimdall has superhuman abilities and ages at a much slower rate. He is also able to see and hear everything happening within the Nine Realms, and can use his abilities to communicate with Asgardians in other parts of the universe.
6 THOR
The God of Thunder himself, Thor (Chris Hemsworth) has demonstrated on many occasions why he is one of the most valuable members of the Avengers. Though he has a hard time getting accustomed to life on Earth, he immediately adopts it as his new home and vows to protect it.
On top of his Asgardian strength, Thor can summon massive bolts of lightning and has the power to wield the mythical hammer, Mjolnir. However, after Mjolnir is destroyed by Hela, Thor has to figure out how to use his powers without it. Eventually he is given a new weapon, the axe Stormbreaker.