After 13 Gyr, it should know whether it was or not
Globular clusters, the Galactic Nucleus and the Halo is where I would go looking for this beast. That's where the oldest stars are concentrated. Some are as old as the universe itself.
Hmmm... We know that supermassive black holes are often found in galactic nuclei, and there are reports of stellar black holes in the centers of GCs too. Maybe these black holes are not a natural by-product of the formation of these objects. Perhaps they are artifacts of very old and very powerful civilizations.
Real Olaf Stapledon stuff.