The Protoss never built robots for warfare besides the Colossi. These giant walkers have been constructed after the Aeon of Strife at the time of the Kalath Intercession, but their power was so fearsome that once the war ended, they were locked away in space, hidden on meteors and moons. With the Zerg now in control of Aiur, the Protoss have recovered the Colossi, using them to full effectiveness.

The Colossus is equipped with a thermal weaponry. When it fires, the heat beams spread out in a tangent and sear enemies in a line. This would prove a ver deadly arsenal agains enemies that come in swarms.

Being constructed with very long legs, Colossi can step up and down cliffs. But this attribute comes with a flaw, as its height subjects it to attacks which could exclusively hit air targets, thus making it vulnerable to assaults from any altitude.