Role in the Swarm
Cerebrates were descended from the original zerg parasites of Zerus that existed before the coming of the xel'naga, albeit being much larger and endowed with much greater intelligence. Upon their creation by the Overmind each cerebrate and the brood it led was given a specific role which in turn shaped the cerebrate's personality. Cerebrates further expanded the zerg hierarchy and came to rely on queens to oversee hive activity and overlords to relay commands to and directly control the brood's minions. While the rigid hierarchy ensured efficiency the permanent death of a cerebrate could induce a complete reversal. Broods that lost their cerebrate frequently became uncontrollably destructive. Cerebrates also oversaw the evolution of the Swarm.
Externally, cerebrates appeared as giant, bloated slug-larvae with numerous purple limbs protruding from the sides. This was merely their external form, and the true form of a cerebrate (a ball of yellow light with extruding tentacles) would only be revealed once the carapace had been destroyed. That being said, the flesh could be regenerated as long as the Overmind willed it, bar abilities that nullified such an ability.
Cerebrates were 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 Torrasque, while another may be able to fill its structures with vital energy. Cerebrates possessed detection abilities similar to those of overlords.
One trait that all cerebrates shared was that of reincarnation. While the Overmind was alive, it could reincarnate a cerebrate through the use of cosmic energy. Slaying a cerebrate with this type of energy prevented reincarnation. Zasz, cerebrate of the Garm Brood, was permanently killed in this way by Zeratul, a Dark Templar. This created a brief mental link between the assassin and the Overmind; Zeratul 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. The Overmind went into some kind of depression following this, and did not recover until the zerg completely destroyed the Garm Brood. Later, the protoss killed other cerebrates in deliberate attempts to "distract" the Overmind.
Although their link with the Overmind granted them virtual invulnerability, it was not without its weaknesses. Cerebrates were not designed to exist without the Overmind, and were unable to sustain themselves for long after its death – a vulnerability which drove them to create a new one following the first Overmind's death.
Fate of the Cerebrates
Following the death of the Overmind at the end of the Great War, Daggoth orchestrated the creation of a new Overmind from the fusion of a number of cerebrates. The Renegade Swarm controlled at least half of the zerg in opposition to Kerrigan. This set the stage for the Brood War.
In this conflict, Kerrigan emerged triumphant, albeit through manipulation of those capable of slaying cerebrates. Those on Shakuras were destroyed as the result of an "alliance" between her and the protoss settling on that world. The UED Expeditionary Force slew some cerebrates during their conquest of Char, preventing their ability to reincarnate through the psi disrupter. Later, during Kerrigan's reconquest of the planet, the new Overmind was slain by the Dark Templar allied with/manipulated by her. Upon the creature's death, the remaining cerebrates were killed by the Dark Templar. The lack of a controlling force was a partial explanation for their deaths.
Some cerebrates survived the Char holocaust, at least for a time. The New Swarm led by Kaloth was one such example, but its power base was destroyed by Raynor's Raiders and protoss forces. Kerrigan also retained at least one cerebrate which aided her in her infested terran project. Still, it wasn't to last. Following the Brood War, all the remaining cerebrates were hunted down and exterminated by Kerrigan's forces and to best knowledge, there are none left. Kerrigan's vision for the Swarm was quite different from that of the Overmind and she had no use or desire to use the cerebrates, not to mention the risk that they might once again try to form a new Overmind. Instead, she replaced them with other intelligent minions—an advanced infested terran, Ethan Stewart, (now deceased) as well as brood mothers, powerful brood leaders.
Some cerebrates were named, others weren't—only after extended service to the Swarm did cerebrates gain the right to a name. Possession of a name was seen as a sign of prestige.
- Araq of the Jormungand Brood
- Auza of the Incubus Brood/Atticus Carpenter of Carpenter's Brood
- Daggoth, "Senior Cerebrate" of the Tiamat Brood and the leader of his own Swarm
- Gorn, of the Baelrog Brood
- Kagg of the Surtur Brood
- Kaloth, leader of the New Swarm
- Nargil of the Fenris Brood
- Zargil of the Sennith Brood
- Zasz of the Garm Brood
- Unnamed cerebrate, created to achieve victory on Brontes IV
- Unnamed cerebrate, created to watch over Kerrigan in her chrysalis
- Unnamed cerebrate, created to secure the Argus Stone
- An unnamed cerebrate in charge of the Grendel Brood was killed by Zeratul at about the same time Gorn was permanently killed.
- Sometime after the Fall of Tarsonis, 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 on Shakuras
- While the psi disrupter was active, the United Earth Directorate killed three cerebrates on Char.