Tiamut, initially referred to as “The Sleeping Celestial,” was created by the legendary writer and artist Jack “The King” Kirby. His first appearance was in The Eternals #18, published in December 1977. Kirby introduced the Celestials as a race of inscrutable, god-like space beings responsible for creating the Eternals and Deviants on Earth. The concept of a fourth, renegade Celestial imprisoned beneath the Earth was a core mystery of Kirby's original run. The name “Tiamut” and his designation as “The Communicator” were later established by subsequent writers, linking him to the Babylonian goddess of the primordial sea, a fitting name for a being of immense, ancient power. His transformation into the Dreaming Celestial was a pivotal storyline in the 2006 Eternals miniseries by writer Neil Gaiman and artist John Romita Jr., which revitalized the characters for a modern audience. His subsequent role as a silent watcher over the X-Men's base in San Francisco was a major plot point in Matt Fraction's run on Uncanny X-Men, solidifying his unique place in the Marvel Universe as a passive, yet profoundly influential, cosmic entity.
The origin of Tiamut is a tale of cosmic scale, differing dramatically between the comic book canon and the cinematic universe.
Tiamut's history is interwoven with the very dawn of sentient life on Earth. He was part of the First Host of Celestials that arrived on Earth approximately one million years ago. Alongside luminaries like Arishem the Judge, Oneg the Prober, and Ziran the Tester, Tiamut participated in the genetic experiments on early hominids that resulted in the creation of two divergent offshoots of humanity: the god-like Eternals and the genetically unstable Deviants. This act set in motion a planetary destiny that the Celestials would return to judge in later eras. Tiamut served faithfully through the Second and Third Hosts. The Second Host arrived around 21,000 BC to check on their experiment's progress and found the Deviants had created a vast, global empire, conquering most of the planet. In response, Arishem the Judge ordered a devastating bombardment that sank the Deviant continent of Lemuria and reshaped the world in a “Great Cataclysm.” Tiamut's fall from grace occurred during this period. The full details are shrouded in cosmic mystery, but it is known that one of Tiamut's fellow Celestials, Arishem's long-forgotten rival, began questioning the Celestials' core mission of forced evolution and judgment. This dissenting Celestial was deemed a heretic. Tiamut, as The Communicator, was ordered to kill him. However, Tiamut hesitated or outright refused, an act of defiance that Arishem and the other Celestials viewed as the ultimate betrayal. For this crime, his life-essence was ripped from his cosmic armor and he was cast out. Another Celestial, Hargen the Measurer, sealed Tiamut's now-dormant physical form deep within the Earth's crust, in a location that would later become the Diablo Mountains in California. He was designated “The Renegade” and his existence was largely stricken from Celestial records, leaving only the legend of the “Sleeping Celestial.” For millennia, he remained in a death-like slumber, his immense power inert. His silent presence was eventually detected by the Deviants, who built a temple above him, and later by humans. During the Fourth Host, when Arishem arrived to pass final judgment on Earth, the combined power of the Asgardian Destroyer armor (inhabited by the souls of all Asgardians except Thor) and the Uni-Mind (a collective consciousness of the Eternals) was unable to even scratch the armor of the Celestials. It was later revealed that the energy blast they unleashed was silently absorbed by the sleeping Tiamut, preventing it from being turned back on Earth and destroying the planet. His true awakening came millions of years later. In the modern era, the Eternal known as Makkari, who had been granted the ability to communicate with the Dreaming Celestial, was manipulated into using his powers to awaken the giant. Upon rising, Tiamut did not seek vengeance or destruction. Instead, he simply stood, silent and motionless, his form towering over San Francisco. He had become the Dreaming Celestial, a being contemplating a truth far beyond mortal or even Celestial understanding, a living monument to cosmic consequence.
In the MCU, Tiamut's origin is fundamentally different and serves a more direct, narrative purpose within the film Eternals (2021). Here, Tiamut is not a fallen member of a Host but rather an embryonic Celestial whose “seed” was planted in the core of the Earth billions of years ago by Arishem the Judge. The entire purpose of life on Earth, from Arishem's perspective, was to serve as an incubator. The energy generated by a large, intelligent, and thriving population was necessary to fuel the gestation of the new Celestial. The planet itself was not a subject of judgment, but a cosmic egg. The process of the Celestial's birth is called The Emergence. When the planet's population reaches a critical threshold, the Celestial awakens and emerges from the planet's core, completely destroying the planet in the process. This act of creation-through-destruction releases an immense amount of energy, which in turn allows Arishem to create new suns and seed countless new worlds with life, continuing the cosmic cycle. To protect this process, Arishem created the Eternals. These synthetic beings were programmed with a deep-seated loyalty to their mission: to protect the host planet's dominant intelligent life (humanity) from the Deviants, a race of predators also created by Arishem that had evolved beyond his control. The Eternals believed they were saving humanity for its own sake. Their memories were wiped after each successful Emergence, and they were sent to a new planet to repeat the process, believing it was their first mission. The Earth-based Eternals, led by Ajak and later Sersi, eventually discovered the true nature of their mission. They learned that their entire existence was a lie designed to facilitate planetary genocide. Tiamut's impending Emergence became the central conflict. The team was fractured: some, like Ikaris, remained loyal to Arishem's grand design, arguing that the sacrifice of one planet was necessary for the creation of billions of new lives. Others, led by Sersi, had grown to love humanity and refused to allow its destruction. Tiamut himself displayed no consciousness during this period. He was a force of nature, a cosmic event about to happen. As the Emergence began, his massive hand and head broke through the Earth's crust in the Indian Ocean. In a final, desperate act, Sersi, channeling the power of the Uni-Mind formed by all the Eternals, used her matter-transmutation abilities to tap into Tiamut's own immense cosmic power. She transformed his entire emerging form into a harmless, marble-like substance, effectively killing the nascent Celestial and freezing his partially-emerged body in place, saving the Earth but defying a fundamental law of the universe.
As a Celestial, Tiamut is a being of near-incalculable power, operating on a scale that dwarfs most other cosmic entities in the Marvel Universe. What is the power level of a Celestial? It is often described as near-omnipotent.
In his prime as a full member of the Celestial Host, Tiamut possessed the standard suite of powers common to his race, making him one of the most powerful beings in existence.
As the Dreaming Celestial, his state is more complex. While dormant, he was still powerful enough to effortlessly absorb an energy blast that would have destroyed Earth. Upon awakening, his power seemed more passive. He did not act, but his mere presence was a source of immense cosmic energy. He was able to communicate with Makkari and later with the X-Men, sharing cosmic truths and passing judgment not through action, but through silent observation and the subtle manipulation of events. He eventually judged humanity worthy, but his ultimate purpose and the nature of his “dream” remain one of the universe's great unknowns.
The MCU's depiction of Tiamut's power is more inferred than demonstrated, as he is never seen in a fully conscious, active state. His power is understood through the consequences of his existence.
The key difference is one of agency. Earth-616 Tiamut is a character who wields his power. MCU Tiamut is the power—a natural, catastrophic event that the protagonists must prevent.
For a being as ancient and remote as Tiamut, “relationships” are defined by cosmic hierarchies, ancient betrayals, and the lesser beings who interact with him.
In the traditional sense, Tiamut has few allies. His primary connections are those who sought to understand or aid him after his long imprisonment.
Tiamut's enemies are beings of his own cosmic weight class.
Tiamut's journey is defined by three key narrative arcs that transformed him from a background mystery into a fully-fledged character.
During Jack Kirby's original saga, the mystery of the “Sleeping Celestial” was a crucial subplot. The Deviants, led by Priest-Lord Ghaur, sought to awaken the entombed Celestial, believing they could control his immense power and use it to challenge Arishem and the Fourth Host. The Eternals fought to prevent this, understanding that unleashing such a being could have apocalyptic consequences. This storyline established Tiamut (then unnamed) as a cosmic “nuclear option,” a figure of immense power whose true nature and history were unknown but whose potential was terrifying. His silent absorption of the Destroyer/Uni-Mind's energy blast was a key moment, revealing that even in slumber, his power was beyond comprehension.
In Neil Gaiman and John Romita Jr.'s influential miniseries, the Dreaming Celestial was finally brought to the forefront. Makkari, desperate for purpose, becomes the catalyst for Tiamut's awakening. The narrative frames this not as an act of evil, but as a cosmic destiny being fulfilled. Tiamut's rise from the Earth is a world-shaking event. But instead of destruction, he simply stops and stands, silent and observing. He communicates his purpose to Makkari: he is no longer a destroyer or a surveyor, but a judge of a different kind. He will watch and wait, and his final judgment will be based on the totality of Earth's existence. This storyline brilliantly subverted expectations, transforming a potential villain into a profound, unknowable cosmic philosopher.
After the events of the 2006 series, Tiamut's massive, inert form remained standing in the bay just outside San Francisco. When Cyclops moved the X-Men to the city and established their new headquarters, Graymalkin Industries, they found themselves living in the shadow of a god. The Dreaming Celestial became a recurring background element and a plot device. Characters would gaze up at him, contemplating their struggles in the face of such cosmic indifference. The climax of this relationship came when the X-Men faced a dire threat and Cyclops, in a moment of desperation, had his telepaths project a simple message to the Celestial: “Save us.” Tiamut responded by communicating with Cyclops, scanning the X-Men and their adversaries, and ultimately deciding to do nothing, allowing the “mutant race to die.” However, this was a feint; his inaction was a form of judgment, deeming the X-Men worthy of solving their own problems. He later protected them from harm, confirming his silent guardianship. This arc solidified his unique role as a passive but deeply significant force in the Marvel Universe.
Due to his nature as a singular, ancient cosmic being, Tiamut does not have as many “variants” as street-level heroes or villains. However, a few notable interpretations exist.