The Progenitors, also known as the Ones Before and the Civilizations of the Unobservable, are an antediluvian race of lifeforms that, according to a few scraps of xenological and paleontological evidence on the edging boundaries of what has ever been explored by nations known to Humans, may have aided in the creation of many (if not all) lifeforms during the young infancy of the Universe. However, with the constant expansion of the Universe since the Big Bang, they have been disconnected entirely from the rest of the xenosphere from the Observable Universe.
A devastating error in the test of the Human Treader Warp Drive series in 100067 CE, which promised users to tread across the entire Universe with speed and calculated agility, landed the experimental ship in the midst of the Unobservable Universe -- several giga-lightyears from the Observable Universe's edge. After taking numerous pictures and transmitting them back through the warp trail (which another promised feature of the Treader, eliminating the need for long-distance hypertachyon transmitters), the ship was annihilated by a spontaneous burst of white-hole energy, with the same Progenitors appearing in the footage.
Anatomy and Physiology
The Progenitors are massive, with the "youngest" being about fourty to fifty kilometers in length, and the "oldest" possibly being the size of entire gas giants and brown dwarves.
((work in progress, will expand lore compatibility and expound more information soon.))