Zerg

The Zerg are a terrifying and ruthless race of biologically advanced, insectoid aliens. Dedicated to the pursuit of genetic perfection, the Zerg relentlessly hunt down and assimilate advanced species across the galaxy, incorporating useful genetic code into their own, and exterminate any species that might corrupt the purity of the Zerg genome.

History
The original Zerg species was discovered on the ash world Zerus, in the center of the Milky Way Galaxy, by the Xel'Naga, a mysterious and ancient race of extragalactic geneticists, after they had abandoned their first experiment, the Protoss, on Aiur. The Zerg organism was a small, larval organism, but it contained the purity of essence sought by the Xel'Naga.

Through Xel'Naga proto-genetic manipulations, the Zerg survived the torrential firestorms of their world and thrived. The Zerg developed the ability to burrow into the spinal fluids of less vulnerable creatures on Zerus, parasitically merging with them. These new bodies would then be used to manipulate their surroundings. The Zerg began to assimilate the genetic strains and processes of these host creatures. However, the Zerg had an undeviating drive to consume only the most advanced species they encountered. Lesser species were eradicated. The Xel'Naga were surprised to find how quickly the Zerg could steer the evolution of their host creatures. They developed armor piercing spines, razor-sharp limbs, and ultra dense carapaces.

Fearful of the chaotic in-fighting that had enveloped the Protoss, the Xel'Naga created the Overmind, an enormous brain-like entity, to bring order to the Zerg. At first it was only a semi-sentient entity created from the instincts and collective sentience of the Zerg, but it quickly evolved.

The Overmind did not directly relay orders to its minions. As new species were added to the Swarm, it began to relay orders through Cerebrates, giant versions of the Zerg larvae. Direct orders were relayed through Queens and Overlords.

Expansion
The Overmind began to think of its future. In order to continue finding new species, it must leave Zerus. Extending its senses into space, it became aware of enormous space-faring organisms. It lured them to Zerus with its psychic abilities, then assimilated them into the Swarm. Soon all the Zerg had the ability to survive in space. The Xel'Naga considered this a triumph. The Zerg had not only survived their weaknesses, they had retained the purity of their terrible overriding essence.

The Overmind extended itself further into space, becoming aware of the Xel'Naga Worldships in orbit above Zerus. The Xel'Naga realized their psionic link with the Overmind had been severed - the Overmind effectively hid itself from their view.

The Overmind sent its minions into space, attacking the unsuspecting Xel'Naga. Despite the ancient race's best efforts, it was overwhelmed as the Zerg crashed into the hulls of its ships. Within a few hours the Zerg laid waste to the Xel'Naga fleet. The greater whole of the Xel'Naga was consumed by the raging, genetic whirlwind of the Zerg, and the Overmind gained their knowledge and insights. Processing thousands of sentient beings into itself caused the Overmind 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.

The Overmind dissected the memories of the Xel'Naga experiments with the Protoss. The Zerg then devoted their energies to seeking out the powerful Protoss in the hope of absorbing them into the Swarm, uniting purity of form and of essence, to create a totally "perfect" being.

The Determinant
The Zerg did not know the exact location of Aiur, homeworld of the Protoss, but they were able to travel towards it, adding new species (such as the Mutalisk) to the Swarm along the way. However, the Zerg Overmind despaired; how could it defeat the Protoss with their powerful psionic abilities, when its own were so limited?

In the shadow of the Protoss lay the Koprulu Sector, a patch of space inhabited by the Terrans. This species had been discovered by Zerg deep space probes. Normally the Zerg would not be interested in such a weak species, but they exhibited a powerful psionic potential. Their probes discovered humans living on over a dozen worlds.

Invasion of the Koprulu Sector
The Zerg slowly made their way towards the Terran worlds. The journey lasted for sixty years, but eventually the massive, extended Zerg Swarm reached the outskirts of the Koprulu Sector. A number of Fringe Worlds were immediately infested.

The Zerg continued to penetrate into the Sector. The Terran Confederacy colony Chau Sara was subtlety invaded first with Hive Spores, before the bulk of the Zerg force arrived to complete the infestation process. The Terrans were defeated although the Overmind was by the Terran response, A Protoss fleet led by Executor Tassadar arrived shortly thereafter and sterilized the planet, effectively ending the infestation. The Overmind ordered its minions not to resist so that it could observe the Protoss in action.

The Confederacy attempted to keep the Zerg presence a secret from its own citizens, enabling the Zerg to infest Mar Sara virtually unopposed. Ironically, certain Terran factions used the Zerg incursion to further their own political ends.

Breakthrough on Char
However, whatever the success against the Terrans, the Zerg were still intently focused on the Protoss. The Swarm's "big break" would come on Char. On Char, the Dark Templar Zeratul assassinated the Cerebrate Zasz, resulting in the destruction of the Garm Brood. The Protoss had struck a keenly felt victory, but it was also their undoing. A brief psychic link had formed between Zeratul and the Overmind at the moment of Zasz's death. Both had been able, to some extent, read the other's mind, and the Overmind had been able to extract the location of the Protoss homeworld of Aiur. Exultant, the Zerg began their preparations for the invasion of Aiur and the fulfilment of their millennia long quest for perfection.

The Invasion of Aiur
As with the Terrans, the Zerg were aided by internal strife within Protoss society.

The Brood War
The Zerg were originally controlled by the Zerg Overmind, who was destroyed by the Protoss Tassadar (at the cost of his own life) at the end of StarCraft Episode III.

By StarCraft Episode IV, it was revealed that the Zerg had formed a new, young Overmind on Char, the adopted Zerg homeworld, but it was captured by the United Earth Directorate in Episode V. In Episode VI, the final act to date, Infested Kerrigan, the self-claimed Queen of Blades, a former human Ghost telepath soldier who had been infested (transformed) into a Infested Terran, had the second Overmind killed and claimed leadership over the entire Zerg Swarm.

With the Terran Dominion decimated, the expeditionary fleet of the United Earth Directorate destroyed, and the Protoss homeworld Aiur conquered by the Zerg with the survivors fleeing to Shakuras, the Zerg currently stand as masters of the StarCraft universe.

Destruction of the Cerebrates
Infested Kerrigan appears to be the undisputed ruler of the Zerg and no longer uses Cerebrates since the death of the second Overmind; the Overmind's Cerebrates having been destroyed. However, it should be pointed out that at least one Cerebrate served her during the Brood War that she was unlikely to kill; she may have also used the services of this Cerebrate in her Infested Terran project.

StarCraft II
The Zerg retreated to Char at the end of the Brood War and have not launched any attacks or made any overt hostile actions for four years. This worries the Terran Dominion, which thinks the Zerg have been "too quiet".

The Zerg continue to inhabit Aiur, however.

Zerg Control
All Zerg are directly subject to the will of the Overmind; it is a biological impossibility for them to oppose its directives. Only Cerebrates (smaller brains), and possibly Overlords and Queens, have sentience, and control a different army (called a Brood), using Overlords as lieutenants to directly control the warriors and workers. The lesser Zerg minions are wholly dependent upon the Cerebrates and the Overlords for order. Should a Cerebrate die, its brood may run amok; the animalistic nature of individual Zerg emerges. In the context of a multiplayer match, when an Overlord dies, a Zerg player loses Control points, and must grow more overlords to replace the loss. Without these control points, additional Zerg units cannot be built. Even Zerg buildings are living organisms, and aren't built but grown. Zerg structures do not cost Control to grow.

Zerg Heroes

 * Infested Kerrigan (the Queen of Blades and of the Zerg Swarm)
 * Daggoth (Cerebrate)
 * Kaloth (Cerebrate)
 * Torrasque (specialized Ultralisk strain)
 * Zasz (Cerebrate)
 * The Overmind
 * Infested Stukov (uninfested)
 * Infested Duran (exact species unknown)
 * Devouring One (specialized Zergling strain)
 * Hunter Killer (specialized Hydralisk strain)
 * Yggdrasill (specialized Overlord strain)
 * Kukulza (specialized Mutalisk/Guardian strain)
 * Unclean One (specialized Defiler strain)
 * Matriarch (specialized Queen strain)

Zerg Broods
Main article: Zerg Broods
 * Tiamat Brood
 * Surtur Brood
 * Fenris Brood
 * Jormungand Brood
 * Garm Brood (eradicated)
 * Grendel Brood (destroyed)
 * Baelrog Brood (destroyed)
 * Leviathan Brood
 * Kukulkan Brood (introduced in StarCraft: Shadow of the Xel'Naga, now destroyed)
 * Incubus Brood (destroyed)

References/External Links

 * Battle.Net: Zerg
 * StarCraft homepage at Blizzard Entertainment
 * Underwood, Peter, Bill Roper, Chris Metzen and Jeffrey Vaughn. StarCraft (Manual). Irvine, Calif.: Blizzard Entertainment, 1998.
 * Neilson, Micky. StarCraft: Uprising. New York and Toronto, Ontario: Pocket Books, 2000. ISBN 0-7434-1898-0 (eBook only)
 * StarCraft campaign editor