"Assaulting an enemy encampment can be a very costly affair, and rather than sacrificing Protoss lives we have developed a robotic war machine, the Reaver, to use as mobile artillery. The Reaver is heavily armored and houses a micro-manufacturing plant to produce tiny, highly explosive drones called Scarabs. The Reaver carries no weapons but a wave of Scarabs can reduce both troops and buildings to rubble in moments."
Reavers are heavy ground artillery, though are not artillery in the classic sense (of terran understanding) in that they don't lob unguided projectiles. In fact, the reaver itself does not mount any weaponry, but instead houses a micro-manufacturing plant similar to the carrier, producing tiny robotic drones known as scarabs. While the reaver looks ungainly, just one of these war constructs can level a colony in minutes.
Tube-like protrusions are located on the sides of the reaver's head, giving the appearance of 'eyes'. These are used to help the reaver navigate. Reavers are limited in mobility, and are often shuttled by protoss air units.
The reaver evolved from a civilian mobile manufacturing unit that was militarized to become a mobile artillery piece, ensuring that fewer lives would be lost when assaulting enemy bases. Somewhat fittingly, reavers are renowned for leveling entire colonies in moments.
This article or section contains information about StarCraft: Ghost, which has been declared non-canon. Elements may be taken as 'flavor lore' however. The content may be significantly out of date. Please do not add speculation to this article, and remember to cite a published source for details.