Huragok

Engineers, called Huragok in the Forerunner language, are the only known non-combatant race of the Covenant.

Summary
While the Prophets guide, direct and manage Forerunner research, it is the Engineer caste who must excavate, unlock and transport Forerunner artifacts. These remarkable aliens are patient, almost completely silent and utterly focused on their task and its religious implications.

Their concentration has been described as "a trance-like reverie" by the few who have witnessed it. They communicate only with Prophets - a fact that may contribute to the balance of power between Elites and Prophets - and will usually ignore anything that is neither a Prophet nor a Forerunner artifact, although they seem to have a general interest in all machines. One observed exception is a high-pitched, keening wail that Engineers will emit should Forerunner objects or structures be threatened.

Some Engineers are used to help construct and repair the Covenant starships from the inside, while in the conjunction with the Drones who construct and repair the ships in space on the outside.

Physiology
The Engineers are an amorphous, purple-skinned species that have six dark eyes, and have 4 tentacles that can split into very small, near-microscopic cilia. The Engineers use these cilia to construct, or repair nearly anything they can grasp. They can take apart whole vehicles and rearrange the entire structure of it in a matter of seconds, and it will still operate. They learn at an unprecedented rate, and store that information for future reference if ever they need to repair the same thing twice.

Engineers are not a tactical threat and are hardly ever seen in combat situations. Interestingly enough, Engineers do not regard humans as enemies. In fact, Engineers aided the Master Chief in the novel, Halo: First Strike.

Appearances
Engineers feature in both Halo: The Fall of Reach and First Strike.

In Fall of Reach, an Engineer is observed dismantling and re-assembling a human car on Sigma Octanus IV.

In First Strike, an Engineer is instructed by Cortana to go with the Chief to repair the reactor of Ascendant Justice. On the way there, it aids the Chief by repairing a spoiled Needler he picked up. Later, another Engineer repairs the shield on the Chief's MJOLNIR armour, which was disabled, apparently by Elites which returned fire while defending Ascendant Justice's bridge.

In the Halo Graphic Novel it is noted that some engineers were stationed on the Infinite Succor. The Spec Ops leader in charge of the exploration said "This is Huragok blood" while exploring the ship. Engineers were originally intended to appear in Halo 1, but due to time constraint issues, Engineers were "left on the cutting room floor." But they were not deleted entirely from the software, and modders have since located the Engineer files on the game disc and spawned Engineers in various configurations, hence the images that may be found.