Stalker

"I am here in the shadows."

- Protoss stalker

The stalker is a Dark Templar cybernetic war machine.

Overview
The fall of Aiur demonstrated to the Dark Templar that more than just stealth and guile were required to defeat the zerg. Hence, the Dark Templar developed the stalker, a war machine inspired by the Khalai dragoon. While dragoons were piloted by crippled protoss warriors, the stalker is controlled by the shadow-essence of a Dark Templar warrior fused into a metal body. Nerazim who control stalkers undergo this process voluntarily, said process involving a ritual which fuses their shadow essence to the machine. This gives them a preternatural degree of control over their new bodies. The process cannot be reversed.

Stalkers are armed with carapace-mounted particle disrupters adept against both ground and aerial targets. These weapons draw upon the power of the Dark Templar’s training and technology to fire lethal blasts of entropic Void energy. Each shot destabilizes matter at a fundamental level, and ultimately tears it apart by disintegrating its atomic composition. The particle disrupters are especially effective against materials with high hardness indexes—like chitinous carapaces or heavy armor plating.

Stalkers have been credited with many fantastic powers since their battlefield début. (as early as 2502). However, only one is witnessed consistently: an ability to instantly teleport, or "blink", from one spot to another. This ability requires augmentation to a stalker, through the implementation of a device called a Void displacer. When enabled, the displacer grants stalkers the ability to fade and materialize instantly at a different location, affording them an unprecedented degree of mobility, perfect for quick strikes against the enemy. The improved mobility allows stalkers to conduct ambushes, catch fleeing foes, and generally engage on their own terms. However, each "blink" generates a flux that taxes the stalker's systems. It must go through a brief recharge period before initiating another displacement.

Stalkers are often used to support zealots on the battlefield.

Game Unit
In-game, stalkers function like fragile, but more agile dragoons. They serve as excellent economy raiders.

Stalkers can dance like a dragoon. This may be enhanced by Blinking, especially in multilevel terrain.

Stalkers are effective against units with low damage per second, especially with Blink micro. The reverse is true for offensive units, especially those with attack bonuses against armored units. Zerglings are cost effective counters to stalkers; the Blink cooldown is too slow to ensure escape.

Stalker/sentry combinations are common in mid-game scenarios.

Legacy of the Void
In the campaign of Legacy of the Void, stalkers can be upgraded to possess a "shadow blink" ability. This causes a stalker to become invisible for a few seconds after blinking.

Legacy of the Void
Additional stalker upgrades may be researched at the twilight council when playing as Vorazun in the Co-op Missions mode of Legacy of the Void.

Quotations

 * See: StarCraft II Stalker Quotations

Development
The concept behind the stalker was that of a "dark dragoon." It took awhile for the specifics to be nailed down.

The design was finessed several times as its asymmetrical shield and legs gave it a zerg-like appearance. This dictated that platinum be made the dominant color in order to distinguish it (which led to platinum being the dominant color for Dark Templar as a whole). However, the shield made the stalker look heavier and more imposing from some angles, while weak and frail from other views. It was eventually settled that the stalker should have a medium sized shield to interfere the least with visual communication.

Eventually, Samwise Didier called for an overhaul, wanting the stalker to be based more on his original concept art. The stalker was thus redesigned, and the new model was revealed at BlizzCon 2008.

Heroes of the Storm
Stalkers appeared in early builds of Heroes of the Storm.

Trivia
The stalker resembles the Shock Trooper from Command & Conquer 3: Tiberium Wars in appearance, purpose (anti-armor ranged fighter), and ability to blink.