Feral Zerg

Feral zerg were zerg that stood under the control of no higher entity. Cut off from the directing will of a cerebrate, a broodmother, or the Queen of Blades, they fell back to the lowest level of their nature and behaved as predators, attacking everything around them and consuming other animals, including other zerg, for nourishment. Control could be reasserted over feral zerg by command strains, even ones as low as the overlord, but until that happened they roamed without purpose beyond survival. They were drawn to psionic emanations and would rush toward their source, a tendency that later made them a weapon to be lured.

Nature#

Feral zerg were defined by absence rather than by any strain of their own: they were ordinary zerg from whom the higher controlling will had been removed. Without that direction they reverted to the most basic level of their instincts and became pure predators, consuming other animals for nourishment and turning on other zerg when no other prey was at hand. Unlike controlled zerg, which depended on the creep for sustenance, feral zerg could persist with only limited creep or none at all, relying on their hunting instinct to survive. Their attraction to psionic emanations was strong enough that they would charge at the source of such energy, a trait that armies and saboteurs would later turn against the worlds the feral zerg overran.

Control was not permanently lost. A command strain, even one as minor as an overlord, could reassert authority over feral zerg and fold them back into a directed force, which is why Sarah Kerrigan and her broodmothers were repeatedly able to reclaim feral packs simply by arriving in strength and exerting their psionic command.

During the Great War and Brood War#

Feral zerg first emerged as a recognized danger during the Great War. When the Dark Prelate Zeratul slew Zasz on Char, the zerg of Zasz's Garm Brood went feral, and the renegades posed such a threat to the Swarm that Daggoth ordered the entire brood eradicated. The same pattern repeated when Tassadar slew Kerrigan's cerebrate: the brood accompanying her turned feral, and she managed to hold control over only small numbers.

The death of the Overmind produced feral zerg on a far larger scale. In the immediate aftermath nearly all the zerg on Aiur went feral and rampaged, killing everything in their path. Even after Kerrigan took control of the Swarm, the zerg on Aiur remained outside her direct command, and when Zeratul returned there in 2504 to visit the Overmind's resting place he found feral zerg guarding and feeding off its corpse. The zerg of the planet Cavir likewise remained feral after the death of their master Daggoth. Feral zerg could also be found burrowed in the wastelands of Mar Sara, believed to have arrived after the planet's purification; when colonists recolonized the world in 2502 they hunted these ferals for sport in the Annual Hydralisk Derby.

During the Second Great War#

The Second Great War saw feral zerg both as obstacles and as resources. A flock of feral mutalisks had lived in seclusion for years on the terran-occupied moon Choss, having survived the Dominion's earlier efforts to wipe out the zerg there; among them was a rare canny mutalisk, and the colonists eventually exterminated the flock after it began attacking them. On a fringe world the terrans nicknamed Goldilocks, acolytes of the Nerazim Lassatar tried to use a xel'naga relic called the psionic lens to impart individuality and self-awareness to captured zerg, but the new individuality reverted the zerg to feral instinct and they overwhelmed their captors before being destroyed in a triggered volcanic eruption.

The greatest wave of new feral zerg came with Kerrigan's deinfestation at Char. As the Swarm splintered, many zerg turned feral; those that had been guarding Kerrigan immediately began devouring everything in sight, including the corpses of zerg killed by Jim Raynor and his men during their escape. After Kerrigan's fall, a Dominion marine group called Meatbag Squadron killed a feral overlord during a raid on the Scantid Pirates on Tarsonis, not realizing it was Purple Eyes, one of the last original Gargantis proximae assimilated by the Swarm, which had regained sentience as it went feral; its mate Green Eyes rallied the region's feral zerg and killed all but one of the squadron in revenge.

Kerrigan repeatedly reclaimed feral packs as she rebuilt the Swarm. Feral zerg were kept as test subjects at the Umojan facility Research Station EB-103, and many broke loose to harry Kerrigan and Raynor during a Dominion attack on the station. On Astrid III, feral zerg developed the swarmling strain of the zergling, a discovery Abathur reported to Kerrigan, who seized telepathic control of the ferals and used them to destroy the local Dominion garrison. On Kaldir the zerg of Nafash's brood went feral after the protoss killed their broodmother, and Kerrigan reinducted them on her arrival. When she returned to Char to take it back from General Horace Warfield, she and the rogue broodmother Zagara fought for control of feral baneling nests and eggs in the acid marsh, and Kerrigan's victory there forced Zagara's surrender. Feral impaler colonies on Marek V and feral brood lords and mutalisks near the Dominion platform Sigma Centari were hunted on Kerrigan's orders so the Swarm could harvest their essence and recover lost strains.

After the war#

During the End War, many feral zerg, particularly those still on Aiur, fell under the control of Amon, who used them to assemble his own zerg brood. In the years that followed, feral zerg became a tool of terran politics. The separatist group the Defenders of Man planted psi-emitters on Dominion worlds to lure feral zerg, exploiting their attraction to psionic emanations, so that the resulting devastation would expose the weakness of Emperor Valerian Mengsk's regime; the Defenders would then sweep in to save the survivors and appear as heroes. They did this first to Antiga Prime, overrunning the world.

Nova Terra uncovered the scheme but was mind-wiped before she could report it. When feral zerg attacked Borea, Nova defended Admiral Matt Horner's base until the Defenders arrived to clear the zerg, and she and her Covert Ops Crew then traced the plot to Tarsonis, by then overrun, where she confirmed the Defenders were using psi-emitters to draw the ferals in. The Defenders lured a massive feral swarm to Tyrador IX, inflicting heavy Dominion casualties before Nova's crew struck the feral hives; the feral zerg were then attacked in turn by the Tal'darim Death Fleet under First Ascendant Ji'nara, who sought to punish the Defenders for provoking them. Nova later returned to Antiga Prime to recover her memories through terrazine, fighting through entrenched feral zerg to escape with what she needed. Feral zerg continued to wander Cavir for years afterward, a standing problem for the Dominion forces stationed there.