This species, first seen in security camera footage discovered on a dead Terran cargo vessel, is one of the fiercest and most dangerous of the Zerg strains. The upper carapace plates of the Hydralisk can open to expose hundreds of spines that are projected with such force that they can penetrate 2cm Neosteel. Fortunately, they move quite slowly on open terrain.

The Hydralisk is easily the most versatile breed for the Zerg. With the ability to strike both ground and air targets, Burrow (once evolved), and health regeneration, the Hydralisk is a force to be reckoned with. Also with their short build times and relatively low cost, they can be produced in mass numbers to overwhelm the enemy.

With the ground/air strike capability, Hydralisks are the best support units in the Zerg race. Combine their attack with Zerglings, Mutalisks, Guardians, etc. and the enemy will have a much more difficult time halting them. Another excellent combination is using Hydralisks with Dark Swarm. Casting Dark Swarm over a large Hydralisk force can increase their lifespans by quite a bit and can be particularly useful against large ranged attack unit groups like Carriers, Dragoons, Goliaths, Vultures, Guardians, etc. Watch out for melee attack units (i.e. Zerglings, Zealots, Firebats) when using this combination since they will have the advantage under the Dark Swarm.

Uprades

Burrow - Burrow can give Hydralisks time to regenerate or set up an ambush.

Missile Attacks - Each upgrade adds +1 to Missle Attacks for a total of +3 when fully upgraded.

Carapace - Each upgrade adds +1 to the Carapace for a total of +3 when fully upgraded.

Muscular Augments - To make sure Hydralisk attack groups can attack or retaliate when needed, get this upgrade to increase their speed so that targets can be reached as soon as possible.

Grooved Spines - Getting the increased attack range upgrade will give the Hydralisks the ability strike the enemy sooner, keeping them at bay or damaging them while they approach. An essential upgrade for the Hydralisk.

Once the ability is evolved at the Hydralisk Den, the Hydralisk has the ability to morph into the Lurker. During the transformation, the Hydralisk can still be recovered, but once it's complete, the Hydralisk is lost.