Sarlacc (Earth-1791)

'“What I am? I am a monument to all your sins.”' The Sarlacc also known as a compound intelligence, is the shared consciousness of the entire Vorcha species which first emerges when the Vorcha reaches the Coordinated Stage. While this compound mind inhabits all Vorcha, it is distinctly embodied in processing nodes of agglomerated Vorcha biomatter known individually as Sarlaccs.

Origin
'“We meet again, young one. I am the last of those who gave you breath and shape and form, millions of years ago. I am the last of those your kind rose up against and ruthlessly destroyed. I am the last Precursor. And our answer is at hand.” - The Primordial speaking with Beyonder'.

Millions of years before the present, the ancient and powerful civilization known as the (???) held a position of stewardship over the Milky Way Galaxy, populating it with numerous lifeforms and watching over their evolution. However, one of their created races, the sapient species known as the Protheans, staged a rebellion against their creators and were successful in nearly wiping them out. The remaining (???) sought ways to render themselves dormant until such a time as they could safely roam the galaxy again.

Around a million years after the downfall of the (???), a being later known as the Primordial—evidently a (???) intelligence embodied in the form of an archaic Sarlacc—was confined to a (???) stasis capsule and placed beneath the surface of a small planetoid at the Milky Way edge by an unknown group of beings, suspected to be ancient Protheans. Meanwhile, most of the last surviving (???) converted their bodies into an organic powder, which would regenerate their original forms at a later time. However, the millions of years that followed rendered the powder defective, and the resurrection process instead yielded malformed, parasitic lifeforms that could assimilate organic matter and survive in a utopian hive mind, yet, with individualism - the nascent stage of the Vorcha.

Personality
"Do I take life or give it? Who is victim, and who is foe?"

Although multiple Sarlaccs have existed throughout time—sometimes contemporaneously with one another—they all share an obscure, complex and highly intelligent personality. When he was first seen by the Master Commander Chief, Garrus Vakarian and Urdnot Wrex, the Sarlacc was calm and collected, if not seemingly sad or mournful, and he spoke with a sullen tone in his voice. He was also quite logical, psychologically analyzing the duo, and trying to convince Wrex of the Halo rings' true purpose, to which Wrex reacted with stubborn pride. Sarlacc showed no irritation to this. Later, though, the Sarlacc showed a more emotional side, basking in his victory at High Charity, and displaying a sinister air of anger when demanding answers from the newly captured Cortana.

Trivia

 * Sarlacc is one of the few extraterrestrials to learn William Lawton's real name.