Nothing is known about the galaxy except for that it is 3 million light years away from Earth and is completely colonized by the Ceph. In the galaxy are over a million Ceph hives, nearly all of them covering three or more star systems.
The southern spiral arm is part of the billion year old Over-Hive Hyperion. An unbelievably colossal hivemind that has countless worlds under its control and a myriad of ships and colonies. Two other colossal but somewhat smaller hiveminds, exist within the galaxy. Which are Over-Hive Coeus on its eastern fringes and Over-Hive Iapetus to the west of the galactic core. The age of Over-Hive Hyperion suggests that it may have been a seeding ship from an even more ancient Ceph.
M33 Galaxy on Wikipedia