Cerebrate

Zerg Cerebrates are powerful agents of the Zerg Swarm, created by the Zerg Overmind for the purposes of controlling Zerg Broods. They manifest the collective consciousness of the respective broods under their command and are therefore inseperable from the Overmind itself; each one has a "piece of the Overmind" within it, each representing one or more aspects of the Overmind's intelligence. Even so, Cerebrates are independent entities and seem to have developed personalities and unique characteristics over time.

Role in the Swarm
Cerebrates seem to be descended from the original Zerg parasites in the form they possessed before the Xel'Naga intervened, albeit much larger and endowed with much greater intelligence. Each Brood was given a specific role based on the personality and talents of its Cerebrate. For instance, the Cerebrate Gorn led the Baelrog Brood, a Brood dedicated to vicious attacks. A Cerebrate has a specific place in the hierarchy of a Zerg Brood: Zerg Overmind, Cerebrate, Overlord, Queen, other Zerg. A Cerebrate cannot directly give orders to most Zerg units, only to the Overlords, Queens and larvae; this necessitates the Overlord as a unit providing 'control', necessary to create new units. A Cerebrate is capable of controlling Zerg on another planet, so long as nothing interferes with its psionic communications. With the permanent death of a Cerebrate, Zerg Broods frequently go insane, but this does not always happen. Sometimes the Zerg become dormant or even exhibit a normal behavior (so long as their Hive Clusters remain intact).

Psionic powers and link to the Overmind
Cerebrates are often (perhaps always) powerful psychics, but these powers are usually limited to a specific area. For instance, one Cerebrate may be able to create and reincarnate the powerful Zerg Torrasque, while another may be able to fill its structures with vital energy. The Psi Disruptor was also able to inhibit reincarnation, at least temporarily. Cerebrates possess detection abilities that are similar to that of the Zerg Overlord.

While the Zerg Overmind was alive, it could reincarnate a Cerebrate through the use of cosmic energy. This type energy is also used by the Dark Templar, who can kill a Cerebrate and prevent its reincarnation. The first time this happened, Zeratul killed Zasz, Cerebrate of the Garm Brood, and he created a mental connection with the Overmind. From this connection he learned of the Overmind's connection with the Xel'Naga and its plans for the Protoss race, while the Overmind learned the location of Aiur in a form it could use. Possibly more information was transmitted in this exchange. The Overmind went into some kind of depression following this, and did not recover until the Zerg completely destroyed the Garm Brood. Since then, other Cerebrates have been destroyed, apparently without similar effects.

Cerebrates appearing in StarCraft
A significant number of Zerg Cerebrates appear in various missions in StarCraft and StarCraft: Brood War, although not all are identified beyond any doubt. Many Cerebrates are also mentioned in the series, including the novels and the instruction booklet of the original StarCraft game; several Cerebrates die in the series.

The player in both Starcraft Zerg campaigns plays as a Cerebrate (specifically as Araq and his Jormungand Brood). In the original Starcraft campaign, the player is created in order to nurture Sarah Kerrigan as she is transformed from a Terran into an infested Terran and powerful Zerg psionic agent. In the Brood War campaign, the player assumes the role of a Cerebrate working under Kerrigan's control.

Cerebrates featured in the series include:
 * "Senior" Cerebrate Daggoth, the only Cerebrate capable or entitled to give other Cerebrates orders. It led the Tiamat Brood. It was responsible for the creation of the second Zerg Overmind. Its current fate after the events in Brood War is unknown, but it is believed to be alive.
 * Kagg, Cerebrate of the Surtur Brood.
 * Nargil, Cerebrate of the Fenris Brood.
 * Araq, Cerebrate of the Jormungand Brood, and second-in-command of Kerrigan, Queen of Blades. His brood is one of the last surviving broods after the war and it is Kerrigan's personal army.
 * Zasz, Cerebrate of the Garm Brood, had a bad relationship with Sarah Kerrigan. Zasz was the first Cerebrate that had ever been permanently killed. Zeratul dispatched it.
 * Gorn, Cerebrate of the Baelrog Brood, and widely viewed as insane, is killed by Zeratul.
 * Kaloth, Cerebrate named in StarCraft Resurrection IV.
 * In addition, an unnamed Cerebrate was killed by Zeratul at about the same time Gorn was permanently killed. In the StarCraft: Enslavers missions, Alan Schezar gained control of another Cerebrate, but it was killed. Early in the Brood War, the Dark Templar killed two Cerebrates studying the Xel'Naga Temple, and finally, while the Psi Disruptor was active, the United Earth Directorate killed three more. These may have been reincarnated by the second Overmind later. Finally, when Infested Kerrigan defeated the second Overmind, its Cerebrates apparently also died.