Huragok

The Huragok (Factitius indoles), known to humans as Engineers, are a pseudo-species of biomechanoid lifeforms created by the Forerunners and a former Covenant client species. As a general rule, Huragok are overwhelmingly peaceful, docile and display a savant-like dedication to their work, with little regard for anything else.

A handful of different Huragok variants have been identified by the Covenant, the most common being the Builder/Engineer type. These Huragok are purple-blue or pink, and specialize in analyzing and repairing machinery. A rarer subtype is the Lifeworker Huragok, which is smaller than the Engineer variant, green in coloration and specializes in medicine. There are other variants mentioned only in Covenant historical texts, namely a larger type of Engineer encountered on gas giant-based facilities, and a sturdier variant that presumably fulfilled some role in the Forerunner military.

History
The Huragok were discovered by the San'Shyuum early on in Forerunner maintenance facilities and were subsequently drafted as a client species. While they would come to fulfill a crucial role in the Covenant as specialist technicians, the Huragok's status in the hegemony at large was more akin to that of tools than true citizens. They would frequently accompany technicians and discovery-priests while reverse-engineering Forerunner technology, as well as being routinely assigned to maintain Covenant ships and facilities. A small number of Huragok were captured by the UNSC near the end of the Human-Covenant War, becoming valuable assets in several of the technological breakthroughs to come.

Biology
Sometimes regarded as a form of semi-biological AI, the Huragok are composed of nanomechanical organ and tissue analogs mostly indistinguishable from their real counterparts.

Psychology and behavior
Depending on the definition, the Huragok are either sapient or semi-sapient, as despite their incredible aptitude in technological matters, they lack some of the traits typically associated with sapient species such as culture, complex introspection or social behaviors.

Communication
Huragok mainly communicate through a form of sign language by manipulating the cilia in their tentacles. While rather challenging for outsiders, members of the Covenant tasked to interact with the Huragok were capable of learning this sign language to some extent, enabling them to communicate with the Huragok. In addition to this, Huragok emit a range of whistles and wails as a secondary form of communication.