One of the most feared teron military units, the Devourer is unique in that it is not actually sentient. It is governed by comparatively simple programming, unlike most Combine military units, which house actual teron consciousnesses. Devourers resemble blobs of mercury or molten lead, but are actually swarms composed of millions of microscopic nanobots, similar to those used in teron projectile weapons. These machines must remain together in a cohesive form to facilitate movement and offense.
The nanobots attack their target at its most basic level, ripping it apart molecule by molecule. Individually, they are no threat, as they expend all of their energy when attacking. However, a full size Devourer can eat through an armored soldier in seconds. Devourers are notoriously hard to destroy, requiring sustained fire to stop. Though the individual nanobots are fragile, it requires the destruction of millions of them to scatter the Devourer and shut it down.
Used as expendable shock troops, Devourers will rush headlong into enemy lines, ignoring blows that would kill regular troops, and eating their way through enemy soldiers and vehicles with frightening speed.