Thanos made an unexpected appearance in an episode of the animated What If...? series, with the Mad Titan becoming a heroic member of the reformed Ravagers under T'Challa's version of Star-Lord. MCU fans might have been startled by the face-turn by Thanos, but there are many powerful variants of him in the comics.
Like most other major characters in the Marvel Universe, significant Thanos variants exist both in divergent realities in the multiverse and within the main Marvel continuity of Earth-616. Some feature very different takes on the character, while others take his lust for power and destruction to shocking lengths.
Updated August 25th, 2022 by Darby Harn: With the MCU headed toward The Multiverse Saga and Avengers: Secret Wars, many variants of iconic Marvel Comics characters will likely appear. Though his story in live-action ended with The Infinity Saga, Thanos may number among them. Like most major Marvel characters, numerous Thanos variants fill out the multiverse, and some make sense to return to the MCU. Thanos variants stand a good chance of appearing in unexpected places, including potentially She-Hulk: Attorney At Law. She-Hulk dealt with a Thanos clone in the comics, and it wouldn't be out of the realm of possibility for her to in the MCU.
Thanos Clone
She-Hulk fought the Thanos clone in She-Hulk #13 from 2006, during a key She-Hulk comic book storyline perfect for newcomers. As a clone, this Thanos possesses the Eternal physiology of the original, which absorbs and processes latent cosmic energy. Even without his iconic and infamous weapons, he's among the most powerful Marvel villains.
She-Hulk dealt with numerous Thanos clones, called the Thanosi, while she presided over a trial in which Starfox, another Eternal, stood for crimes he allegedly committed across the cosmos.
Thanos (Earth-829)
Comic book fans know Hercules enjoys immortality thanks to his Olympian heritage, and in Earth-829, he lived into the 24th century. There he encountered the acolytes of an older Thanos who also promises to live forever thanks to his Eternal mutant genes. This Thanos appears to share the Earth-616's basic powers and abilities.
He also commands several devoted followers as he does in the main Marvel Universe, with Hercules fighting a zealous villain determined to steal the Nega-Bands from the late Captain Marvel's tomb.
Captain America Thanos
Thanos counts among the best variants from the What If...? comic book series, mostly because of how unlikely he is. What If? Infinity - Thanos introduces a version of Thanos who in his reality is Captain America. He possesses all Thanos' manifest strength, stamina, and speed, on par with the Hulk.
In the story, Thanos joins the Avengers after brokering a deal to combine their forces against an invading alien army. With Captain America out of the picture, he takes possession of the shield, and the image of a Cap Thanos alone makes him one of the wilder versions of the character in the comics.
Punisher Thanos
The Punisher counts among the most unforgiving characters in the Marvel Universe, but when Thanos became a superpowered variant of him in Earth-18138, he took the concept to another level. This powerful version brought Thanos' considerable strength and cosmic determination to his quest and added lots of firepower.
This Thanos quested for good and justice though, influenced by a Frank Castle who went back in time to raise Thanos as a baby. Together, they formed an unlikely force for good in the cosmos. Things went sideways as they tend to with Thanos though, and he ultimately killed his adoptive father.
Zero Day
The Thanos of Earth-15061 exceeds other variants in how truly cruel he was. Thanos obtains a Cosmic Cube and uses it to form a pair of Iso-Gauntlets which he then uses to kill half the superheroes on Earth. He proclaims it Zero Day for the new world order and establishes himself as ruler of a devastated Earth.
The Iso-Gauntlets enhanced his natural powers and abilities, including his ability to manipulate and project energy into damaging blasts or protective force fields, something the MCU avoided when he didn't have the Infinity Gauntlet.
King Thanos
The King Thanos of Earth-TRN666 embodies everything the character believes in the comics. Armed with his skill in numerous fighting styles and weapons, Thanos is equal to the best martial artists in the Marvel Universe. He eventually defeated all of his opponents and killed virtually every living being in the universe.
That left him alone with his few surviving minions. The Cosmic Ghost Rider served among them, and this character eventually went back in time to raise the child Thanos as the Punisher.
Thanos The Just
Thanos The Just wields all the power his Earth-616 version does, including uncommonly depicted powers like flight and telepathy. He differs in one major respect. This Thanos serves only peace and justice. Rather than becoming one of the most powerful Avengers villains in Marvel Comics, he rules as a benevolent leader determined to protect others.
This kind Thanos variant shows the extent to which the cruelty of others actually undermined the potential of his power and ambition. Using his intellect and strength for good, he remakes the galaxy into a peaceful place.
Poisoned Thanos
Thanos led the Poison Hive, an aggressive parasitic alien race from Earth-17952. In the Venomverse storyline in the comics, his ambitions went far beyond killing half of life: he sought to control the entire Earth-616 universe. Like the Earth-616 version, this Thanos variant clung to a terrifying desire to impress Death which resulted in unimaginable destruction.
This Thanos gained control of the alien symbiotes that spawned Venom and Carnage, and successfully transformed Carnage into a poisoned version, a massive accomplishment without the aid of the Infinity Gauntlet.
Heroes Reborn
In the alternate Earth-TRN852 reality born from the 2021 Heroes Reborn crossover event, Thanos acquired the Infinity Rings. Thanos converted the powerful Infinity Stones into rings in this reality, which retained their signature dominions from Earth-616 but also projected energy constructs that echoed that of the Power Ring from Green Lantern comics.
The rings collectively gave Thanos the same potential he achieved in The Infinity Gauntlet storyline, among the most important Marvel Comics events ever, though he didn't get the chance to actualize his power thanks to Doctor Spectrum.
Ultimate Thanos
The Thanos from the Ultimate Comics universe of Earth-1610 remains one of the best versions of the character, as his goal isn't to please anyone else, but simply to indulge in his own gratification. Thanos seeks the Cosmic Cube to make him the ruler of all existence. He's immediately successful, conquering Earth and turning its population into mindless slaves.
Thanos rarely succeeds completely in his ambitions, making this powerful variant unique among the others. Thanks to the genius of Reed Richards, Mr. Fantastic, the Cosmic Cube he constructed actually kills him by using it.
Omega
Thanos' quest to impress Death pales only in his desire for more power. Omega, a clone of Thanos that incorporates the power and genetics of Galactus, easily ranks among the most powerful Thanos variants in the multiverse and the most crucial cosmic beings in the Marvel Universe.
Galactus possesses the Power Cosmic, granting him cosmic awareness as well as dominion over matter and energy on unimaginable scales. Omega hails from Earth-616 and was a product of Thanos' need to test himself against the power and potential of his enemies.
Zombie Thanos
Zombie Thanos suffers from the zombie plague that completely overran Earth-2149. In addition to his normal abilities, including some proficiency in magic, he gained a frightening immortality thanks to becoming a zombie. He also transformed many others into zombies as he joined in the rampage that occurred in his reality.
Thanos evidently devoured much of the Marvel Universe alongside the Zombie Galacti, who all acquired the Power Cosmic by feasting on Galactus. This allowed Thanos to teleport across space and time at will, making him extremely powerful.
Thanoseid
Thanoseid combined the powers of both characters, giving him the Eternal strength of Thanos and the immortal physiology of the New Gods. Armed with the Anti-Life Equation and unparalleled determination, this frightening fusion produced a character with no scruples and few if any weaknesses for heroes to exploit.
Comic fans know that Darkseid from DC Comics and Thanos have a fair amount in common, as creator Jim Starlin acknowledge Darkseid inspired Thanos. Those similarities were exploited in the Amalgam Comics crossover between Marvel and DC back in the 90s to create one of the best and most powerful versions of Thanos ever.
Heart Of The Universe
The Heart of the Universe possesses inconceivable powers as a cosmic entity. When Thanos acquired that power for himself, he became virtually a god. This nearly omnipotent version of Thanos emerged in Earth-4321 and gave Thanos complete control of some of the most elemental aspects of creation.
Thanos was able to time travel and completely absorb some of the most powerful beings in the entire Marvel multiverse, including the Living Tribunal, Eternity, and Infinity, all among the most powerful entities in existence.
Astral Regulator
After acquiring the power of the Astral Regulator, a cosmic artifact created by the most powerful being in Marvel Comics, the One Above All, Thanos becomes a god in every sense. He uses the artifact to absorb the power and knowledge of the One Above All along with all other cosmic beings, including Death.
By the end of his journey, this Thanos variant becomes virtually unrecognizable as he takes on the appearance of his vanquished foes like Galactus and Death.