Huragok

Huragok, also known as Engineers and Savants, are the only known non-combative race amongst the Covenant forces. They were artificially created by the Forerunners. They are a peaceful race, and frowned upon the Human-Covenant war. They are silent beings, and speak in a form of sign language which very few species can understand(apart from the Unnunogy and themselves). Huragok are incredibly intelligent and are very good mechanics. The Yanme'e were replaced from the usual duties as engineers by the huragok and placed in the military. This sparked some conflict between the Yanme'e and the Huragok. One Huragok,ironicly named "Lighter Than Some", was a victim of this aggression. As a peace treaty to the humans, he also made the Brute Chopper. It was later used by the Jiralhanae as a weapon. The "voices" are made up of small clicks in the air sack of the Hurogak.

Origns
It is unkown how the Huragok were absorbed into the covenent, but it can be presumed that there DNA were stolen from forerunner computers and artifacts. They are, as already stated, carbon based artifical life forms which only manage to scratch sentience. It has been speculated by the Halo 3 terminals that they were never meant to be sentient, and reffered too by the Didact as "a useless waste of good carbon".

Uses in the covenent
The Huragok are never seen in any of the halo games(unless modded)- with the exception of halo wars, where they are nicknamed "engineers". Because of their few appearances, not much is known about the physiology, apart from the fact they can split millions of cilia at a time to make a "beam" which can repair covenent builldigs.

Furthormore, it is known how they can fly, or "float", from one place to another. The process is caused by a massive gas sack on the back of the Huragok which breaks down hydro carbons(mainly methane) and other hydrogen rich chemicals to cause the Huragok to litrally become lighter than air. Additenely, the Huragoks can control where they move by six tentecales which are also filled with gas.

Appearance in games
The Huragoks, as mentioned above, are never seen in any of the Halo games with the exception of Halo wars, where they only feature as a non combatant support unit. The only way to actully come in contact with a huragok in the first person shooters is to mod the game or down load Halo CE, in which you can make your own levels and choose the Huragok(though named the "MegaFloatyThing" in the game) and actully place it on a level. However, since the Huragoks have no death animation or attacking animation, they will not die if you shoot them but will only emmite a small clicking sound.