Spoilers for What If..?

Ultron became one of the most powerful beings in the entire MCU multiverse in the latest episode of What If...?, but do any of his many powerful variants from Marvel Comics compare? Ultron's entire existence is predicated on evolving into more and more advanced forms, both in the mainstream continuity of Earth-616 and beyond.

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Some of these variants are beyond powerful, reaching a cosmic level not unlike that of his animated counterpart on What If..?. Others are more incremental improvements on the core concept of Ultron, but each iteration of the classic Avengers villain becomes harder and harder to defeat in any universe he finds himself in.

Ultrog

Kangaroo The Conqueror romances the Scarlet Witch in Marvel Comics.

Ultrog is a powerful version of Ultron from Earth-8311, the same reality that produced Peter Porker, Spider-Ham. In this anthropomorphic universe, Ultrog has all the same basic powers and abilities as his Earth-616 counterpart, which are vast.

He has superhuman strength and durability thanks to his adamantium frame. He can also fly, or in the case of this universe, scale skyscrapers like the Empire State Building. He is a creation of Kangaroo The Conqueror, one of the most powerful - and fun - variants of Kang The Conqueror in comic books.

Ultimate Ultron

Ultron-6 attacks in Marvel Comics.

The Ultimate Ultron, or Ultron-6, was at the time of his appearance in Avengers #66–68 the most advanced version of the android supervillain. This is the first variant of the character to use adamantium to strengthen his robotic shell, making him virtually invulnerable to most practical forms of attack.

He could also change his shape and form at will thanks to a device that rearranged molecules. Ultron-6 had the ability to fly thanks to an interchangeable flight module he could augment his body with.

Yellowjacket (Ultimate Comics)

Yellowjacket Ultron leads Ultimates in Ultimate Comics.

Another ultimate version of Ultron exists, this one from Earth-1610, the reality of Ultimate Comics. This version of Ultron is called Yellowjacket, an android version of the superhero identity of Hank Pym.

This Ultron wasn't as diabolical or advanced as his 616 counterparts, but he had the ability to fly and could also shrink in size or grow to huge heights. He was also very strong, with his strength and durability escalating as his size fluctuated upwards or down. This Ultron also had razor-sharp claws laced with a toxin to use against his enemies.

Ultron Pym

Ultron fuses with Hank Pym in Marvel Comics.

An even more insidious amalgamation of Ultron and his creator, Hank Pym, emerged from the "Rage Of Ultron" storyline in mainline Marvel continuity. In this story, Ultron literally fused with Pym, combining Ultron's considerable strength and power with Pym's boundless intellect and power as Ant-Man.

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Hank Pym's ethics and morals have long been suspect in the Marvel Universe, and in this form, he reaches rock bottom. He is able to shapeshift back and forth from Pym to Ultron, an ability he uses to deceive the Avengers and nearly destroy them.

Annihilation Conquest

Ultron attacks Star-Lord in Marvel Comics.

Ultron became one of the most powerful cosmic beings in the Marvel Universe when his consciousness transferred into the mind of Adam Warlock. Warlock's powers and abilities are considerable. He can fly in space faster than the speed of light and generate energy blasts that were strong enough to contest Thanos even when he had the Infinity Gauntlet.

Warlock also derives enormous power from his symbiotic connection to the Soul Stone, which enabled Ultron to expand his already tremendous powerset to include the mystic arts.

Earth-10943

Ultron Earth-10943 confronts the Avengers in Marvel Comics.

In the reality of Earth-10943, Ultron becomes so powerful that he is insurmountable to the combined power of both the Avengers and Kang The Conqueror. This Ultron has amassed so much power he was able to kill all the Avengers of his world and take over.

His armor takes on the appearance of The Destroyer from Asgard in some ways, though it's unclear if there is any direct connection. Ultron's success in this reality is such that he destabilizes time thanks to Kang's repeated and futile attempts to defeat him, a development with intriguing potential for the MCU.

Age Of Ultron

Ultron killing Captain America and Iron Man in Age of Ultron.

One of the darkest future timelines in Marvel Comics is the "Age Of Ultron" reality in which Ultron succeeds in conquering the world. While the powers and abilities of Ultron are essentially the same as his Earth-616 version, he achieves far more than his mainline iteration.

He is able to go back in time and attack the Avengers in the past, disrupting history and casting the world into a dystopian nightmare controlled by him. He also commands an army of drones, which he uses to destroy New York City, including many Avengers like Janet Van Dyne, who is a powerful version of Captain Marvel in this reality.

Extremis Ultron

Extremis Ultron emerges from rain in Marvel Comics.

Ultron would incorporate the advanced technology of Tony Stark's Extremis armor during The Mighty Avengers run in the early 2000s. During this time, he was able to take on a techno-organic appearance that could become truly human in appearance. He also took on a female form that strongly resembled Janet Van Dyne, the Wasp.

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Via the Extremis armor, Ultron can manipulate matter with direct thought. He can also generate energy blasts and force fields that are so strong they are virtually invulnerable. Ares famous ax broke against one of them.

Ultron Forever

Ultron becomes King of Asgard in Marvel Comics.

One of the most powerful versions of Ultron became the King of Asgard. Ultron Forever emerges in an alternate future where Ultron enslaves Earth and conquerors Asgard with the help of Loki. With the power of the All-Father, Ultron is nearly god-like. His biggest advantage comes through the Odinforce.

The Odinforce is truly cosmic in scope, with the ability to stop time, manipulate reality, and even bring people back from the dead as Odin did with Jane Foster after she died at the end of her service as a powerful variant of Thor.

Galactus Ultron

Ultron-Galactus speaks to Annihilus in Marvel Comics.

Perhaps the most powerful variant of Ultron of all is a version fused with Galactus. This Ultron was seen fused with the world eater in Marvel Universe 2001 Millennial Visions #1 in an alternate reality where the Silver Surfer reconstituted the android by combining his pieces with Galactus.

Ultron-Galactus possesses truly infinite power by virtue of the Power Cosmic, which gives him the ability to manipulate, harness, and unleash matter and energy on a molecular level. This version of Ultron could literally destroy worlds and needed to in order to feed himself.

NEXT: Spider-Man's Comic Book Villains, Ranked From Most Laughable To Coolest