Overmind

"Awaken my child, and embrace the glory that is your birthright. Know that I am the Overmind; the eternal will of the Swarm, and that you have been created to serve me."

- The Overmind

The Overmind, or known in the prophecy as the Great Hungerer and as the Great Betrayer by Amon, was the leader of the Zerg Swarm.

Creation
"The zerg were... altered. A single overriding objective was forced on them... the destruction of our people. The Overmind was formed with thought and reason but not with free will. It screamed and raged in a prison of its own mind."

- Ouros to Dark Prelate Zeratul

The Overmind was created by Amon and his followers on Zerus to bring order to the zerg and guide them into merging with the protoss. At first it was only a semi-sentient entity created from the instincts and collective sentience of the zerg, but it quickly developed intellect and personality. The Overmind was created with intelligence and the ability to reason, but its free will was undermined by an overriding directive to destroy the protoss. This was part of a greater plan by Amon to remold creation in his own image. The Overmind learned of Amon's plan through scattered and confused images, which the Overmind ultimately formed into a more coherent narrative. The Overmind disagreed with its directive because it knew the zerg would be destroyed once the protoss were, but could do little to resist.

The Overmind was not an automaton, and had broad latitudes in its thinking. However, "iron-clad" compulsions prevented it from considering rebellion. The Overmind used "cracks" in these controls to support the goals of the zerg over Amon's.

Development and Rebellion
"Though I have born witness to the passing of countless millennia, the temple which you must assault is older by far. For it was constructed by my creators, the Xel'Naga..."

- The Overmind to a Cerebrate.

The Overmind did not directly relay orders to its minions. As new species were added to the Swarm, it began to relay orders telepathically through cerebrates, giant versions of the larvae. Direct orders were relayed through overlords. Over a matter of centuries, the zerg consumed or eradicated Zerus's biosphere. The Overmind knew that if it were to extend the Swarm, it would have to depart the world. The arrival of behemoths in the Zerus system provided the opportunity the Overmind sought–lured to Zerus, the creatures were assimilated into the Swarm, allowing the zerg to survive in space.

Before Amon could complete his work on Zerus, his fellow xel'naga learned of his plans and attempted to stop him. Amon retaliated by making the Overmind aware of the xel'naga worldships in orbit. Driven by its need to consume, the Overmind commenced its attack, catching the xel'naga completely off guard. Within a matter of hours, the zerg overran their defenses and laid waste to the xel'naga fleet.

The Overmind absorbed thousands of xel'naga into itself, gaining their knowledge and insights and causing it to grow much more powerful. It learned the secrets of the sacred khaydarin crystals, and began to incorporate the energies of these crystals into its own. Through the knowledge gained from the xel'naga, the Overmind was able to increase the level of sentience in many of the higher zerg strains, while still keeping them fully under its control.

Despite Amon's eventual defeat at Ulnar, the Overmind remained bound by its directive to assimilate the protoss. The zerg devoted their energies to seeking out the protoss in the hope of absorbing them into the Swarm, uniting purity of form and purity of essence, to create a totally "perfect" being.

Hunting Humanity
The Swarm traveled in the direction of the protoss homeworld, though they did not know its specific location. As they traveled, the zerg wreaked havoc upon the galaxy, destroying or assimilating countless numbers of species they encountered and laid waste to hundreds of planets. As the Swarm added ever new strains to its formidable army, the Overmind was uneasy. The protoss possessed formidable psionic powers, an advantage the zerg could not offset. It sought a way to counter this advantage, but found no answer among the strains it devoured. On another front, the Overmind came to increasingly rely on its cerebrates, which took a greater role in directing the Swarm.

All changed when one of its deep-space probes encountered humanity, a frail race that lived under the very shadow of the protoss. Humanity had a great psionic potential and the Overmind ordered the assimilation of the terran worlds to gain the ability to fight the protoss on its own terms. It took the Overmind sixty years to reach the series of worlds inhabited by the terrans, sending out a scouting brood to determine the locations of their worlds.

The Overmind subtly infected the terran world of Chau Sara with spores as a prelude to invasion. The zerg infested or killed most of the populace and had sent minions to other terran worlds by the time the protoss discovered what had happened and responded. The Overmind, anxious to learn all it could about the protoss, held its minions back and let the protoss hamper the initial infestation process. The protoss destroyed all life on the surface of Chau Sara. The decisive action of the protoss pleased the Overmind, which marveled at how the protoss could bring about such devastation. The Overmind pulled its forces back to see how humanity and the protoss would react next.

Arcturus Mengsk sought to use the zerg as a weapon of war against the Terran Confederacy. To this end he acquired psi emitters, a device which amplifies the powers of a telepath, enabling them to attract zerg from a considerable distance.

In the midst of its invasion, the Overmind turned its attention to the terran planet of Brontes IV, which had resisted the swarm's attempts to conquer it. Using its youngest cerebrate and Nargil of the Fenris Brood, the Overmind captured the protoss Judicator Syndrea and repelled 7th Fleet from orbit, forcing them into their stronghold on the planet. However, it discovered that the cerebrate Auza of the Incubus Brood had been taken over by another intelligence named Atticus Carpenter. While the Overmind saw this as a curious experiment, it sought to destroy this new cerebrate to end its rebellion. Meanwhile the Overmind ordered a parasite implanted within the dropship of the terran Black Morgan, which led the Swarm to the final outpost of the New Dresdin Outlaws and 7th Fleet. In a final push, both factions were annihilated by the Swarm. The Zerg Swarm then turned it attention to the Carpenter Cerebrate, overwhelming the lesser brood and ending Carpenter's insurrection.

Agent of the Swarm
"For I have found a creature that may yet become the greatest of my agents. Even now it resides within a protective Chrysalis awaiting its rebirth into the Swarm."

- The Overmind

The zerg had not yet reached Tarsonis, capital world of the Confederacy, when they were drawn there by the emitters. The protoss arrived, intending to destroy all life on Tarsonis, but Mengsk had his own plans. His Sons of Korhal, under the leadership of the increasingly politically unreliable ghost Sarah Kerrigan, would attack the protoss, preventing them from destroying the zerg. In turn, the zerg would destroy the Confederacy. The plan was successful, but Mengsk abandoned Kerrigan to the zerg. Kerrigan was not killed by the zerg, only captured and infested.

In Kerrigan, the Overmind finally found a weapon to combat the protoss. More importantly, though, it had found a way to free itself and the zerg from Amon's insidious influence. Although the Overmind had no concern for the other races, it knew that Amon ultimately intended to exterminate the zerg once they had served their purpose, and the Overmind thus sought to undermine his plans.

The Overmind created a new cerebrate with only one purpose in mind; to protect the chrysalis which now held the captive Kerrigan. The Overmind told the cerebrate that as long as the chrysalis and the creature inside survived, the cerebrate would also continue to live.

The Overmind moved the chrysalis and the rest of the Swarm to Char, whose remote location and convoluted terrain would protect it from its enemies.

The sleeping Kerrigan produced powerful psionic emanations, drawing the attention of such enemies as the Terran Dominion and Raynor's Raiders.

Kerrigan also drew the attention of Dark Prelate Zeratul to Char, who were able to initially hide their presence from the zerg.

Kerrigan, now the Queen of Blades, emerged from her chrysalis during an attack by Raynor's Raiders. The Overmind referred to her as "the undoing" of its enemies and ordered the deaths of all the invading terrans. However, Kerrigan allowed Raynor to leave with his life.

Kerrigan's mind had been damaged by the Ghost Program during her training, and she wished to undo the damage and access her entire range of powers. She intended to raid the Amerigo to learn how to undo this damage. Zasz took issue with this plan, however, reminding her that she was just a servant, and that her wishes did not take precedence over the Overmind's mission. Kerrigan reacted badly to this pronouncement, but the Overmind allowed her to carry out her desire – while she had retained most of her spirit, she could not stray from the Overmind's will.

A New Weapon
"My children, the hour of our victory is at hand. For on this world of Aiur shall we incorporate the strongest known species into our fold. Then shall we be the greatest of creation's children. We shall be... Perfect."

- The Overmind

Once she had expanded her mind, Kerrigan could detect the protoss who had been hiding on Char.

Zeratul and High Templar Tassadar conspired to perform a "weapons test" against the zerg. They had discovered the purpose of the cerebrates and believed that only Dark Templar energy could permanently destroy one. Tassadar distracted Kerrigan while Zeratul slew Zasz. This created a psionic link between the Overmind and Zeratul. Each learned the other's secrets, but the Overmind's mental defenses kept Zeratul from learning everything.

The shock of permanently losing a cerebrate threw the Overmind into a state of mental shock. It did not emerge until the remnants of the Garm Brood had been destroyed.

Upon reaching Aiur, the Overmind told its new cerebrate the purpose of the invasion: it intended to assimilate the protoss thus making the Swarm "perfect". In order to accomplish this task, the Overmind had to be "made manifest" on Aiur, and it needed the khaydarin crystals to do so. The Swarm acquired a crystal for the Overmind.

The Overmind ordered its forces to clear the hallowed ground upon which stood the original protoss temple on Aiur (site of where the xel'naga first set foot on Aiur) and place the khaydarin crystal in its place. Only there could it be made manifest. The crystal was placed, after which the Overmind dove upon Aiur like a bomb and implanted itself on the surface.

The Fall
The protoss response coalesced following a short-lived civil war. Tassadar, with Dark Templar led by Zeratul, and Raynor's Raiders, made the final assault. Praetor Fenix and Zeratul staged a preliminary assault by permanently killing two cerebrates. With the defenses weakened, the allies struck directly at the Overmind, but only managed to destroy the Overmind's outer shell at the cost of heavy casualties. The Overmind prepared to escape through a warp rift and the attack verged on failure. Tassadar channeled the energies of the Khala and the Void into a gigantic ball of energy that destroyed the Overmind and his physical self. Some of the corpse was sucked into the closing rift.

Some of Tassadar's higher psionic functions merged with those of the dying Overmind. This rendered any future manifestations of Tassadar unclear.

A second Overmind was formed after the first one's death.

For many years afterwards, the Overmind's gigantic rotting corpse remained a site of zerg activity, with creatures both feeding on and defending it.

Zeratul's Visit
"I have come to tell you of this creature's... courage."

- Ouros to Zeratul.

On the eve of the Second Great War, Zeratul returned to Aiur to extract its memories, first from the Overmind's tendrils, and later from its cortex. The dark templar sought information to clarify a prophecy he found on Ulaan. When he tried to commune with the cortex he was met by Tassadar's spirit who not only revealed an apocalyptic vision of the future, but also explained the Overmind's motivations during the Great War and its interest in Kerrigan. The Overmind stated that Kerrigan was the key to save the universe from Amon.

The End War
"Now you see. With the essence of the great betrayer, your people fulfill their purpose. My host body is forged. With it, I bring an end to the cycle. An end to infinite suffering."

- Amon

During the End War, Amon corrupted the Khala and took control of Aiur along with the Golden Armada. His forces constructed machinery to create his hybrid host body on top of the Overmind's corpse, using the Overmind's dead flesh during the creation of the host body. Void shards were placed around the site to drain life from Amon's zerg defenders, converting it into void energy to feed the host body to further aid in its creation. Hierarch Artanis and the Daelaam took up assault positions around the Overmind's corpse, and an orbital bombardment obliterated Amon's host body shortly after it awoke, leaving most of the Overmind's corpse a charred crater.

StarCraft
The Overmind exists as an immobile structure in the last mission of StarCraft. In-game, if the Overmind is destroyed, appears on its place an unselectable unshelled Overmind that lasts for approximately 5 seconds. It serves as the advisor for zerg players.

StarCraft II
In StarCraft II, the Overmind's portrait is available as a player profile. There are two Overmind models within the game–an alive (a structure) and a dead Overmind (a doodad). The tendrils are a separate structure. During the "Echoes of the Future" mission, Zeratul visits the dead one, and after the mission is concluded, the alive one appears on a flashback in the ending cinematic.

Development
The corpse of the Overmind seen in StarCraft II: Wings of Liberty is the largest zerg structure created by the design team. It underwent a redesign from its appearance in the previous game, the rationale being that it was to feature the most distinct SC1 features while allowing enough areas for the textures to be shown off and compared to the new zerg buildings. The giant eyeball was another liberty taken with the new art. The thought was it seemed more responsive and alive than a giant exposed brain.

Other
Concept art of what appears to be a deceased Overmind exists for StarCraft: Ghost.

The Overmind's remains appear as a contestable territory in RISK: StarCraft.

The Overmind served as the basis for Abathur's appearance in Heroes of the Storm, namely the idea of an immobile hero with global powers.

The Overmind is referenced in Hearthstone: Heroes of Warcraft in the flavor text of the card Infested Tauren. The text compares the Overmind to the Old Gods of the Warcraft mythos.

Powers of the Overmind
"Truly, no Zerg can stray from my will. For all that you are lies wholly within me."

- The Overmind to Zasz.

It was biologically impossible for the zerg to oppose the Overmind's directives. Although the Overmind was technically a living being, it was really a bodiless entity that embodied the whole will of the zerg species.

It was also capable of opening warp rifts for transport of itself and its broods.

The Overmind also created Abathur.

The Overmind was capable of seeing the future, although this was based mainly around it seeing some of Amon's plans when they were in contact.

The Overmind could only be killed by Void energies. Tassadar channeled these energies through the hull of the Gantrithor in order to slay it.