Lekgolo (Earth-2042)

The Lekgolo are a species of small, sentient colonial worm-like beings that can join together to form purpose specific assemblages, known as subsistence gestalts. Each Lekgolo is an individual organism, about 1.4 meters long, with its own central nervous system. Lekgolo are also able to arrange themselves within machinery and use their combined intelligence to pilot or control it. One of the most successful and culturally enigmatic sentient species in the galaxy, the Lekgolo became the first species to be annexed into the Covenant in 7784 BBY.

Source

 * https://www.halopedia.org/Lekgolo