The Stalker is a mechanical warrior that can fight both ground and air units. It has the Blink ability, which allows it to instantly teleport across the battlefield in order to escape a losing battle or finish off a weak enemy.
The dark templar are a branch of the protoss race that refused to surrender their individuality to the encompassing psionic gestalt of the Khala. In ages past they were exiled from the protoss homeworld of Aiur. They eventually found a new home on the distant planet Shakuras.
Denied the support of the great forges and armories of Aiur, the dark templar were forced to find new ways to defend themselves from a hostile universe. By focusing their inner psionic strength and drawing power from the Void the dark templar learned to mask their presence and strike unseen from the shadows.
The defiant exiles perfected techniques to spread terror and confusion among their enemies by assassinating leaders and destroying vital structures. Ultimately the dark templar came to rival even the mighty zealots in combat.
However, the overthrow of Aiur has proven that guile alone cannot defeat a foe as relentless as the zerg. Inspired by the ancient and honored dragoon walkers the dark templar have begun to build war machines of their own. The stalker is a machine controlled by the shadow-essence of a dark templar warrior fused into a metal body to protect his people.
Swift and deadly, stalkers have been credited with many fantastic powers in recent conflicts. Nevertheless the only one that has been witnessed consistently is the ability to instantly teleport or 'blink' from one spot to another. This ability enables stalkers to strike from unexpected quarters, catch a fleeing foe, or escape an unfavorable encounter.
The deadly particle disruptors mounted on the stalker's carapace are adept at crippling both ground and air targets. Ambushes by groups of stalkers have brought fiery doom upon many attack wings that thought themselves safe from retribution.