Dawn Hunter

Dawn Hunters are a semi-mythical group of automated self-replicating war machines, supposedly responsible for the reduction or even annihilation of entire extraterrestrial civilizations in the Orion's Arm universe.

Etymology
There is no official explanation as to why the Dawn Hunters were named that way. However, dawn might refer to either the distant past, when the galaxy was 'awakening' with intelligent life or the fact those hunters would have attacked any interstellar civilization that was on this dawn.

Nature
There is no direct evidence for the existence of the Dawn Hunters, with all the information about them coming from hearsay and speculation. If real, they only certain thing is that they consist of self-replicating machines and that they attack less advanced civilizations.

Apart from the accounts of the Muuh civilization, who cannot be trusted due to their tendency of distorting even historical accounts for the sake of sensationalism, hints of past nanoswarms are the only evidence supporting the existence of the Dawn Hunters. Even if such evidence showed that they did in fact exist, it would still not prove that they are still alive.

Evidence
No ships hull belonging to them have been found, and there is not much physical evidence that they existed at all or that they developed into a hostile supercivilization. Skeptics point out that many attacks by autowars can be traced back to the ruins of the now extinct civilization HIE636MZE, which was more primitive than the Terragens.

Technology
Though the Dawn Hunters are implied to reached technological levels labeled as godtech in-universe, there is no evidence that they understand the nature of exotic mass. This has prevented them from building wormholes or developing reactionless drives.

Legends
According to folklore in the Terragen Sphere, the Dawn Hunters were built tens of millions of years ago somewhere in the galactic core by unknown creators. Their original purpose was that of scouting the Milky Way to intercept any alien misbehavior according to their creators' standards, as well as protecting it from harmful nanotechnology such as gray goo. However, another sinister purpose was that of eradicating any civilization that used the aforementioned technology.

Supposedly, there were three groups of Dawn Hunters, each possessing a directive ruling a fraction of the Milky Way: Some exoarchaeologists have hypothesized that the some Dawn Hunter clades exterminated obsolete clades. Clades equal in power did not fight each other.
 * Platonic Directive - Ruled by the "logics", they favored the emergence of efficient super-intellengences such as Jupiter Brain megastructures. They destroyed any failed, inefficient culture.
 * Aesthetic Directive - Ruled by the "aesthetics", they valued complexity and protected naturally-evolved, life-harboring planets. They destroyed any culture that did not become more complex over time.
 * Enigma Directive - Ruled by the "enigmas", they were never understood by any species. One hypothesis suggests that they were "just a joke" made by their creators.