While the Magog did not themselves destroy the Commonwealth, they certainly gorged themselves in feasting on its remains. Since their catastrophic attacks in the waning days of the Nietzschean uprising, the Magog have roamed through the Known Worlds nearly unchecked, launching devastating raids against populated worlds only to retreat again, leaving devastation in their wake. Thus far, no political or military entity has been strong enough to check their depradations, though the worlds of the Than Hegemony and more powerful Nietzschean Prides stay relatively safe. But despite causing widespread death and destruction, the Magog have not expanded their former range in a concerted fashion, aside from turning a handful of former Commonwealth territories such as Double Happiness, Dyhedra, and Zinn's World into breeding worlds For their own mysterious reasons, the Magog largely prefer to live on their own planets in the former Quarantine Zone. The other significant change since the Commonwealth's fall has been the conversion of some Magog to the new religion of Wayism (see People of the Way, Political Formations). Unfortunately, Wayism's tenets of peace and cooperation have only appealed to a tiny minority of Magog, while vast majority remain as violent and bloodthirsty as ever. [update-over a billion Magog on the breeding world of Dyhedra were recently killed when their solar system was nova bombed by their former victims, a group of child warriors living on a nearby abandoned High Guard space station. The station has since become a protectorate of the restored Systems Commonwealth, with the governments of Sinti and Castalia helping rehabilitate the station and its inhabitants.]
The most frightening and formidable adversary yet faced by Commonwealth civilization, the Magog are coarse-furred bipeds which average 1.5 meters in height. The Magog secrete paralytic venom from their fangs and are also armed with razor-sharp claws, superior senses which include echolocation abilities, swift reflexes and physical strength a Nietzschean would envy. They're also incredibly resistant to injury and damage and extremely intelligent, though Magog cunning seems almost entirely directed at killing other sentient beings or using them as unwilling hosts for their progeny.
The Magog are all one gender, and reproduce by laying eggs in the paralyzed bodies of large organisms, preferably sentient ones. The Magog "parent" then watches over the host for the time it takes for its young to hatch and eat their way out of the host organism, which in the process dies a slow, agonizing death. Interestingly, the resulting Magog young seem to contain small amounts of DNA from the host as well as the Magog parent. The rate at which Magog offspring grow to physical adulthood is believed to be a function of how much food is available to the young.
The origins of the Magog are shrouded in mystery. All attempts to trace the migration route of the Magog back to their place of origins have ended in failure. The Magog currently control large swathes of space in the Andromeda and Milky Way galaxies, but are barred by the Treaty of Antares from crossing the Quarantine Zone established to demarcate the edge of Magog territory.
Magog society seems to be little more than an aggressive all-consuming horde. The Magog produce no art, no music, no literature. It's not known how such an aggressive, uncooperative species could have developed the spaceflight capabilities and sophisticated technologies the Magog are known to possess. In fact, some researchers theorize that the Magog are not a natural species at all, but rather some kind of bio-engineered weapon, programmed to replicate themselves and destroy everything they come in contact with. But only the Magog know for certain, and they've steadfastly refused to answer questions regarding their own origins.