Marvel Comics is always pushing the envelope by creating scores of new characters that take the best aspects of any given background, including the ever-popular science fiction genre. While sci-fi heroes like Adam Warlock, the Guardians of the Galaxy, and the Fantastic Four are often celebrated, the villains of the genre are essential to its success.
From towering Celestial beings that devour entire planets to evil doppelgangers from space, Marvel Comics has no shortage of science fiction-based supervillains. While many of these characters are terrific, some stand out as the very best Marvel has to offer.
10 Terrax
Terrax the Tamer is an underrated hero in the Marvel Universe who serves as a powerful enemy of the Fantastic Four. Hailing from an alien world, Terrax gained incredible superpowers when he was imbued with the power cosmic after becoming Galactus's new herald.
The very best parts of Marvel's cosmic stories come to life in the character of Terrax, whose alien background is quite intriguing. He also serves as a terrific counterpart to Galactus's other prominent herald, the Silver Surfer, possessing none of his qualms about harming innocent life.
9 Ego The Living Planet
There is nothing more deeply rooted in science fiction than a planet that has come to life. That is precisely the premise of Ego the Living Planet who, as his name implies, is a supervillain who takes the form of a sentient planet, often appearing as an enemy of Thor.
In Marvel Comics, Ego often attempts to expand the borders of his powers by destroying other planets in his way, thereby forcing various heroes to stand in his way. The character lends himself quite well to sprawling, sci-fi epics, and even served as the main antagonist in 2017's Guardians of the Galaxy Vol. 2, where is was portrayed by Kurt Russell.
8 MODOK
Originally a scientist known as George Tarleton, MODOK was born after performing extensive physical experiments on himself, becoming a Mechanized Organism Designed Only for Killing. As MODOK, Tarleton has been a frequent enemy of Ant-Man, the Avengers, and Iron Man. The supervillain also recently made his live-action debut in Ant-Man and the Wasp: Quantumania.
MODOK represents the futuristic robotics side of the sci-fi genre, having altered his body to no longer even resemble his original human form. As an elevated life form, MODOK believes himself to be both physically and mentally superior to the rest of humankind, representing the next age of human evolution.
7 Ultron
The rogue AI known as Ultron is one of the most important Marvel Comics villains of all time. Created by Hank Pym, Ultron desires to wipe all humans off the face of the Earth and replace them with beings made of metal. The popular villain made headway with comics fans, leading him to appear in the MCU film Avengers: Age of Ultron where he was voiced by James Spader.
Like many sci-fi epics dealing with futuristic robots, such as The Terminator, Ultron represents humankind's fear of being replaced by its own advanced creations. Many Marvel stories include the so-called "ages of Ultron," wherein the rogue AI unit attempts to create a new world centered around metal rather than flesh.
6 The High Evolutionary
Dr. Herbert Wyndham, a.k.a. the High Evolutionary, is a mad scientist in Marvel Comics who believes that he can unlock the next stage of human evolution through a series of heinous experiments. The character pops up several times throughout Marvel's history and recently made his live-action debut in Guardians of the Galaxy Vol. 3, played by Chukwudi Iwuji.
The High Evolutionary has dabbled in many sci-fi elements, including cloning, genetic reformation, and has even created several new species in the Marvel Universe. As a result of his often cruel experiments, the High Evolutionary has even created several Marvel characters, including Rocket Raccoon.
5 The Magus
Adam Warlock is one of Marvel's better-known heroes with roots in the science fiction genre, but his evil doppelganger, the Magus, has also made his mark in the comics. The Magus represents any evil that Adam Warlock once possessed and has made frequent attempts to destroy the universe, including in the 1992 Infinity War crossover event
Science fiction often deals with evil doppelgangers and cosmically powered super-beings, with the Magus falling into both of these categories. Imbued with the same cosmic power as the benevolent Adam Warlock, the Magus is one of the most dangerous supervillains in the entire Marvel Universe.
4 The Skrulls
The Skrulls are one of Marvel Comics' oldest supervillains. The shapeshifting aliens made their debut all the way back in Fantastic Four #2, where they proved just how easily they could take the forms of humans. Since then, the Skrull Empire has played into several well-known comic events, many of which had a heavy sci-fi influence.
The Skrulls were involved in the storyline known as the Kree-Skrull War, a storyline quite reminiscent of sci-fi epics like Star Wars or Star Trek. Moreover, the aliens have also played into the existential fear often dominating the sci-fi genre, with their ability to take the form of other creatures leading to several shocking revelations in the 2008 Secret Invasion event.
3 Kang The Conqueror
Kang the Conqueror is a time-traveling supervillain who often serves as a major antagonist to the Fantastic Four in Marvel Comics. Secretly the 31st-century scientist Nathaniel Richards, the Kang has a delightfully confusing origin story in Marvel Comics that includes elements dealing with time travel, futuristic technology, and even the multiverse.
Kang is one Marvel character who seems to have his hand in every element of the sci-fi genre. Through his various time-traveling antics, he has even taken the form of other villains throughout the centuries, including Pharaoh Rama-Tut, Immortus, and the Scarlet Centurion. The popularity of the character has led to his live-action appearances in the Marvel Cinematic Universe, played by Jonathan Majors.
2 Thanos
Thanos is not only one of Marvel's greatest science fiction characters of all time but also one of the best villains ever. The Mad Titan is an alien villain who has fallen in love with Lady Death, leading him on a conquest to destroy half of all life.
As a character, Thanos leans heavily into many popular sci-fi elements. As an alien creature hailing from an ancient race of beings he possesses incredible extraterrestrial technology that makes him quite dangerous to the heroes of the Marvel Universe.
1 Galactus
Galactus, the Devourer of Worlds, is a cosmic entity that, as his title implies, consumes entire planets to sustain himself. Towering through the cosmos, Galactus often uses heralds like the Silver Surfer and Terrax the Tamer to do his bidding. The character's immense popularity has led to many iterations of the villain appearing in video games and movies.
Galactus is deeply rooted in the science fiction genre, with his character coming complete with elements of space travel, cosmic beings, and futuristic technology. He is an immensely terrifying entity and one of the greatest villains in Marvel's long line of sci-fi-inspired characters.