Hydralisk

The hydralisk was a versatile front-line combat strain of the zerg, forming the backbone of the Swarm's onslaughts with its resistant carapace and ranged spine attack. Evolved from the peaceful slothien, the hydralisk became one of the most fierce and sadistic of all zerg strains, acting as the Swarm's shock troops. To terrans across the Koprulu Sector, the hydralisk symbolized the power of the zerg more than any other creature. (StarCraft; Project Blackstone; The Teacher; StarCraft Field Manual)

Origin and physiology#

The hydralisk was a zerg evolution of the slothien, combined with seven or eight distinct and diverse organism strains. The slothien had been a peaceful herbivore, but the hydralisk became one of the most fierce and sadistic strains in the Swarm. As part of its evolution, the strain's endocrine and adrenal systems were altered so that chemicals pumped into its bloodstream effectively forced it to live in a perpetual fight response. Some variants could overcharge this specialized endocrine system to substantially increase their aggression and savagery. (Project Blackstone; StarCraft; StarCraft Field Manual)

Hydralisks were covered in armored plates. An average hydralisk in 2499 measured about 5.4 meters long. Early hydralisks were smaller and leaner than those that followed, and bore single scythes rather than the tri-bladed scythes of later eras, as well as an imposing, colorful crest. Despite their relatively sluggish nature, hydralisks could climb vertical surfaces, and continued genetic manipulation of their musculature increased their locomotion by up to a quarter, both on and off creep. Their muscles and tendons were strong enough to resist many weapons while retaining the flexibility of leather. (StarCraft; The Teacher; StarCraft: Speed of Darkness; StarCraft Field Manual; Cold Symmetry; StarCraft II: Legacy of the Void)

Weapons#

The hydralisk's deadlier weapon was its volley of armor-piercing spines. Each spine was 30 centimeters long, and hundreds were stored beneath flaps in the strain's upper carapace plates. Before firing, the flaps folded back and the hydralisk dipped its head, signs that gave its foes a few seconds of warning. The creature possessed roughly 4,000 muscles, against a terran's 629, and used a portion of them to launch spines with enough force to penetrate two centimeters of neosteel at a range of over 300 meters, sometimes reaching half a kilometer at velocities greater than a C-20A rifle and approaching hypersonic speed. These spines had evolved from the slothien's defensive urticating hairs, could be grooved for increased range, and were highly poisonous. (StarCraft; StarCraft: Ghost: Spectres; The Teacher; Hydralisk (StarCraft II official site); StarCraft Field Manual)

In close quarters, the hydralisk attacked with tri-bladed scythes grown from the relatively soft ribs of the slothien and hardened through genetic manipulation. Connected to fast-twitching striated muscles, these high-density bone blades struck with great power even in restricted spaces such as tight corridors or trenches. The strain could also use its jaw as a weapon, with an estimated bite force of 5,000 pounds per square inch capable of cutting through flesh, bone, and even neosteel. Hydralisks were further observed spreading a webbing that encased and constricted a target, allowing the victim to be restrained and carried away for infestation. (Hydralisk (StarCraft II official site); StarCraft: The Dark Templar Saga: Shadow Hunters)

Tactics and evolution#

Hydralisks moved relatively slowly over open terrain, and terran tactics against the strain stressed the need for siege tank support, and only trained soldiers were to approach them. Hydralisks were sometimes supported by infestors. (StarCraft Compendium; Hydralisk (StarCraft II official site))

As the backbone of the Swarm, the strain was subject to constant evolutionary refinement. Before the Brood War, hydralisks gained the ability to mutate into lurkers. The strain changed drastically in the transition to the Second Great War, growing more bone claws and a bulkier figure, and during that conflict the ability to become lurkers was temporarily lost everywhere except the Leviathan Brood, where the link between hydralisks and lurkers was inherent. After the End War, some hydralisks were given the essence of the noxious strain of ultralisk, gaining toxic abilities and a changed appearance. By the Battle of Adena, the hydralisks of the Niadra Brood had a different physique from their Swarm counterparts, being longer and slimmer with shorter scythes, and firing their spikes from their hands rather than their upper carapace plates. (StarCraft: Brood War; StarCraft Field Manual; StarCraft II: Heart of the Swarm; StarCraft II: Legacy of the Void; StarCraft II: Shadow Wars)

History among the terrans#

The first recorded encounter between terrans and hydralisks took place aboard a cargo vessel, where the creature was captured by the derelict ship's security cameras. Hydralisks established themselves in terran culture to a notable extent thereafter; sometimes colloquially called "hydras," their skulls could turn up as trophies, as on an ore loader on Sorona. (StarCraft Compendium; StarCraft (comic series); Broken Wide)

Project Tamed was a Terran Dominion attempt to use controlled hydralisks as living weapons, but it backfired. The control proved to be feigned, and the creatures had in fact never been removed from the command of the Queen of Blades. (The Teacher)