Ymir stormed into the Marvel Universe in the pages of Journey into Mystery #97, published in October 1963. He was co-created by the legendary duo of writer Stan Lee and artist Jack Kirby, the chief architects of Marvel's Silver Age. Drawing directly from the foundational texts of Norse mythology, specifically the Prose Edda and Poetic Edda, Lee and Kirby envisioned Ymir not just as a monster, but as a living piece of mythology. In the original myths, Ymir (or Aurgelmir) is the first being, born from the venom that dripped from the icy rivers of Niflheim and solidified in the void of Ginnungagap. The gods Odin, Vili, and Vé would later slay him, using his body to create the world.
Lee and Kirby brilliantly adapted this concept for their burgeoning Marvel cosmos. Instead of being slain to create the world, their Ymir was a perpetual threat who was defeated by Odin to save the world. This established him as a recurring antagonist for thor and a cornerstone of the Asgardian lore they were building. His immense scale and raw, elemental power made him a perfect visual spectacle for Kirby's dynamic, “cosmic” art style, cementing his image as one of the most imposing physical threats in Thor's entire rogues' gallery.
The in-universe origin of Ymir, while rooted in the same mythological bedrock, differs significantly between the prime comic continuity and the cinematic universe.
In the primordial dawn of the universe, long before Asgard was forged, there existed the mystical Well of Life within the cosmic void known as Ginnungagap. From the mists and energies of this nexus, two fundamental beings emerged. One was Ymir, formed from the chilling ice of the realm of Niflheim. The other was surtur, forged in the searing flames of Muspelheim. Ymir was the first Frost Giant, a colossal entity of living, sentient ice. As he slept, his body spawned the first generation of Frost Giants. This race, born of his elemental flesh, would come to populate the realm of Jotunheim. During this same era, a cosmic cow named Audumbla nourished herself by licking the salty ice of Ymir's form. Through her licking, she uncovered and freed Buri, the first of the Asgardian race and the grandfather of Odin. This act created an immediate and eternal enmity between the two races; Ymir's very being had given rise to his greatest future enemies. Buri's descendants—Odin, Vili, and Ve—rose to challenge Ymir's dominion. They engaged the ice giant in a cataclysmic battle that shook the foundations of the nascent Nine Realms. The three brothers, wielding immense power, managed to defeat Ymir, shattering his form. They imprisoned his life essence within a mystical ring of fire on the cursed world of Nastrond. For millennia, Ymir remained trapped, his consciousness dormant. However, Ymir's nature is cyclical. He is not a being that can be permanently destroyed. He can regenerate from a single particle of ice, given enough time and ambient cold. His destiny is forever intertwined with his fiery counterpart, Surtur. Prophecy dictates that when Surtur unleashes his Twilight Sword to bring about Ragnarok, the resulting destruction will melt the barriers of Ymir's prison, allowing him to be reborn and unleash an eternal winter upon the ashes of the Nine Realms, thus starting the cycle anew. This eternal dance of fire and ice makes Ymir less a simple villain and more an inescapable cosmic constant.
The Marvel Cinematic Universe (Earth-199999) presents a far more streamlined and visually-driven origin for Ymir, omitting the detailed cosmology of the comics. Here, Ymir is established as the ancient progenitor of the Frost Giants of Jotunheim, but the specifics of his creation from Ginnungagap or his relationship to the birth of the Asgardians are not mentioned.
His first appearance is in the prologue of Thor (2011). During Odin's narration of the war between Asgard and Jotunheim in 965 A.D., a colossal, horned Frost Giant is briefly shown leading the charge against the Asgardian forces. While unnamed on-screen, this figure is identified as Ymir in the film's official art books and supplementary materials. He is depicted as a massive, bestial creature, more a living siege weapon than a sentient king. He is shown being struck down during the battle that ends with Odin seizing the Casket of Ancient Winters. This depiction establishes his historical role as the leader and likely ancestor of his people but provides no further depth.
Ymir makes a second, more direct appearance in Thor: Ragnarok (2017). When Surtur is resurrected by Thor and unleashed upon Asgard to destroy Hela, the fire demon's rampage seemingly summons or creates another version of Ymir. As Surtur grows to his full, city-sized height, a giant ice creature, visually identical to the one from the Thor prologue, rises from the icy depths beneath the palace to confront him. This creature, again identified as Ymir, engages Surtur in a brief, titanic struggle before being utterly shattered by a single blow from Surtur's Twilight Sword.
The MCU's adaptation serves a different narrative purpose. It uses Ymir as a visual shorthand for the immense scale of the threats facing Asgard. His appearance in Ragnarok is not about his personal history but about demonstrating the god-like power of the fully-realized Surtur, who dispatches the “father of all Frost Giants” with contemptuous ease. This simplifies the character, removing his sentience and his complex cyclical relationship with Surtur, reframing him as a powerful monster rather than a cosmic entity with a will of his own.
As a primordial being born at the dawn of time, Ymir is one of the most physically powerful entities in the Nine Realms, rivaling beings like Odin and Surtur in raw might.
Ymir's power is absolute in its domain: the fundamental force of cold. He is not merely a user of ice magic; he is ice.
The MCU's Ymir is a being of immense physical power, but the breadth and nuance of his abilities are significantly less explored compared to his comic counterpart.
Thor prologue, he is seen smashing through Asgardian soldiers and fortifications. In Thor: Ragnarok, he is strong enough to momentarily halt the advance of a fully-powered Surtur, a being who would go on to destroy the entirety of Asgard. His durability is also impressive, as he withstands the initial impact of Surtur's emergence, though he is ultimately no match for the Twilight Sword.True “allies” are a foreign concept to a primal force like Ymir. He operates on a scale beyond mortal alliances, but he has key relationships and has been manipulated into temporary partnerships.
Ymir's only true “affiliation” is with the cosmic cycle of destruction and rebirth. He is a fundamental part of the engine of the universe as understood by the Asgardians. He represents the “ice” aspect of the “fire and ice” doomsday scenario that is Ragnarok. He is the leader, by default, of the forces of Jotunheim when he is active, and his mere presence unites all Frost Giants under a single, destructive purpose.
Ymir's debut story arc established the core tenets of his character. When a foolish human accidentally melts a wall of ice containing Ymir's essence, the primordial giant is reborn on Earth. He immediately begins a rampage, intent on creating a new ice age. This attracts the attention of Thor and Odin. The storyline delves into the history of Ymir's first defeat by Odin and his brothers. Odin reveals that if Ymir and his nemesis, Surtur, were to ever meet on Earth, their combined presence would shatter the planet. The climax of the arc sees Thor fighting a desperate battle against Ymir while Odin works to defeat Surtur in his own realm, preventing the apocalypse and ultimately trapping both entities once more. This storyline was crucial for establishing the cosmic stakes of Thor's world.
Considered by many to be the definitive Thor epic, Walt Simonson's “Surtur Saga” features Ymir in a pivotal role. Surtur forges his massive Twilight Sword and begins a warpath across the Nine Realms, aiming to set the entire cosmos ablaze. As part of this plan, he orchestrates the release of Ymir. The two titans, enemies by nature, form a terrifying alliance of convenience. They plan to destroy Asgard and then fight each other for dominion over the ashes. Ymir leads an army of Frost Giants in a direct assault on Asgard, forcing Thor, Odin, and Loki to fight side-by-side to defend their home. The sight of Ymir and Surtur marching together across the Rainbow Bridge is one of the most iconic images in Marvel history. The event culminates in Odin sacrificing himself to trap Surtur (and by extension, Ymir), saving the realms but at a terrible cost. This storyline cemented Ymir's status as a top-tier cosmic threat.
While Ymir himself does not play a direct, personal role as an antagonist in the main Fear Itself storyline, the event is deeply tied to his legacy and his people. The core plot involves the Serpent, Odin's long-forgotten brother, returning to plunge Earth into fear. One of his chosen “Worthy” is Attuma, who is transformed into Nerkkod, Breaker of Oceans. Nerkkod's forces are bolstered by Frost Giants who are magically transported to Earth. Later in the event, in the tie-in series The Mighty Thor, a desperate Thor makes a deal with Odin to gain more power. As part of this, Odin dispatches his brother Cul, The Serpent, to Nastrond, where Ymir is imprisoned. The Serpent attacks the ice giant, tearing out his stomach and entrails to use as a component in a ritual, demonstrating the horrifying power levels at play in this cosmic conflict. It was a grim reminder of Ymir's presence and vulnerability to other god-like beings.
Ultimate Comics: Thor, where he was presented as the “Mother of the Frost Giants.” This version was a monstrous, gigantic being who was slain by Odin in the past, with his heart becoming the Casket of Ancient Winters. This interpretation maintained his role as progenitor but altered the specifics of the lore to fit the grittier, sci-fi tone of the Ultimate Universe.