A cerebrate is a highly intelligent alien creature from Blizzard Entertainment's popular real-time strategy video game, Starcraft and its sequel/expansion, Brood War.
Physically, a cerebrate resembles a giant wrinkly slug with no distinguishable features or sensory organs. They are somewhat flattened out and taper to one narrow end, although whether this is the front or back, or if such terms are even applicable, is unclear. The cerebrates are created by the Zerg Overmind as needed to act as governors and generals, routing its orders and instructions through them to control the vast Zerg Swarm when the Swarm grew too large for the Overmind to control it all directly. The Cerebrates in turn route their orders through semi-intelligent flying creatures called Overlords, which directly control up to sixteen Zerg creatures. In this way they each can command millions of Zerg creatures. All of this communication is done telepathically, and no creature in the Swarm has the ability to defy the will of the creature above it in the hierarchy, even when given a suicidal order.
Cerebrates do not have any means of defending themselves except through the brood they control. If caught out in the open they are extremely vulnerable to attack, as they cannot even move quickly enough to be of any use in escaping. However they are usually well protected, both by the creatures they command and also by two specialized versions of Creep Colonies, the Sunken Colonies and Spore Colonies, which act as powerful fixed emplacements for attacking land and air targets respectively.
Additionally, a cerebrate cannot actually be permanently killed under normal circumstances because the Overmind can resurrect a dead cerebrate at will. However, the energies wielded by the Protoss Dark Templar have been shown to be able to disrupt the connection between the Overmind and its cerebrates, which not only negates the ability of the Overmind to resurrect the slain cerebrate but also temporarily silences its connection to the rest of the living cerebrates. This leaves them confused and leaderless, as they have come to depend on the omnipresent Overmind as a source of constant motivation and direction. A cerebrate can also be permanently killed by conventional means if it is slain after the Overmind has been killed. Otherwise cerebrates appear to be immortal.
If a cerebrate is killed, its brood may do one of two things. One option is to rampage uncontrolled, attacking everything in sight until the brood is completely destroyed. However, without the intelligent leadership of the cerebrate, their actions are random and disorganized and they can be overcome by an organized and well-planned counter-offensive. Other times the brood sits quietly, doing nothing because it has no orders to do anything. The Drones even stop harvesting minerals and vespene gas.
The Overmind appears to be to the cerebrates a father figure, a benevolent dictator, a commander in chief, and a source of direction and purpose. They are all unfailingly loyal to the Overmind, and appear to have no other goal or desire other than to please it and make it proud of them. This makes the Zerg the most unified and organized of the three races in Starcraft, and therefore the most potentially dangerous.
Although the cerebrates are created with complete loyalty to the Overmind, they do have free will and independent thought. All cerebrates are equals with each other, and they cooperate completely, assisting each other when necessary, whether through advice or lending each other members of their individual broods. Daggoth in particular has been shown to breed a particularly hardy strain of Hydralisk, a number of which he lends the player during an early Starcraft Zerg mission.
Cerebrates possess the power to open warp gates through space in order to allow themselves and their broods to cross interstellar distances. Zasz mentions that this method of travel is "unsettling" until one gets used to it. Some Zerg creatures can fly under their own power, and others travel inside the massive carapace of Overlords, which act as transport vehicles, in order to reach orbit and the warp gate. How the cerebrate itself reaches the warp gate is unknown.
There are six named cerebrates, although there are certainly more of them in total. In particular, the multi-player mode of Starcraft has two additional Zerg broods, bringing the total to eight, and although they must both have cerebrates leading them neither is named. Additionally, the player is a ninth cerebrate. Due to the number of cerebrates killed during Starcraft and Brood War, there must have been several more.
Each Cerebrate appears to be created with a specific purpose. The player in particular is tasked with guarding Infested Kerrigan, both during her chrysalis incubation and while she acts as an agent of the Overmind. Additionally:
- Daggoth appears to be the first among equals, the Overmind's right hand and most experienced and capable of the cerebrates. Daggoth's brood is normally restricted to deep space combat, and is tasked with the protection of the Overmind itself. Daggoth gives the player assistance and advice during the game. He controls the Tiamat brood.
- Zasz is the only other cerebrate who is given a voice in Starcraft. Zasz appears to have been created to prevent overconfidence in the Swarm, as he is always the first to bring up problems and difficulties their plans may face. However he is not merely an overcautious nay-sayer, as he proposes alternate strategies and direction which could increase their probability of success. These personality traits bring him into conflict with the strong-willed and more gung-ho Infested Kerrigan during the plot of the game. Zasz controls the Garm brood, which is the primary assault force of the Zerg.
- Nargil controls the Fenris brood, which act as hunters and trackers for the Swarm and locate new life forms to absorb and assimilate. Nargil is not given a voice or personality in the games.
- Gorn controls the Bælrog brood, which acts as a berserker terror squad for the Zerg. Gorn's brood is bloodthirsty and aggressive in the extreme, and are sent to strike fear into the enemy and demoralize them before the main assault begins. Gorn is not given a voice or personality in the games.
- Araq controls the Jormungand brood, which is the primary support force of the Zerg. They support and reinforce the primary assault force. Araq is not given a voice or personality in the games.
- Kagg controls the Surtur brood, which is the heavy support force of the Zerg. They are unleashed as reinforcements when the Zerg encounter heavy and organized resistance which is difficult for the primary assault and support forces to deal with. They are only used when necessary, however, as they rampage unchecked across friend and foe alike. Kagg is not given a voice or personality in the games.
The greatest weakness of the cerebrates appears to be their complete dependance on the central authority figure of the Overmind to give them direction and purpose. At the end of Starcraft, the Overmind is killed by the Protoss High Templar Tassadar, leaving the rest of the Zerg leaderless, directionless, and scattered. Unsure of what to do without the central leadership of the Overmind, Daggoth and some of the others merged with each other in an attempt to create a new Overmind to lead the Zerg.
However, due to the intervention of Infested Kerrigan (whose loyalty to the Swarm died with the Overmind), this new Overmind was captured by human forces before it matured and was used to control the rest of the Zerg by placing it under the influence of massive doses of drugs and powerful psychics. The only cerebrate unaffected by this was the player, whose connection to his charge, Infested Kerrigan, was apparently stronger than the artificial control the rest of the Zerg were under. This allowed Infested Kerrigan to control a Zerg brood (she did not appear to have the ability to control them directly herself), and eventually take control of the rest of the Zerg after the new Overmind was destroyed. Many cerebrates died in the meantime, killed by conventional weapons without an Overmind to resurrect them.