MAGOG, aka the Mobile Anti-Guerilla Operations Group, was a fusion-powered locomotive and several train cars originally destined for Colombia as a gift from the US for the War on Drugs. Skydark hit before it could leave, however, and it remained hidden in redoubt for nearly a century until The General found it. He formed a military unit with the same name and used them to enact his dream of rebuilding civilization in Deathlands.
The etymology of both the names Gog and Magog remains uncertain.
The ma- at the beginning of Magog may indicate a land, or it may mean "from", so that Magog means "of the land of Gog" or "from Gog". Gog may originate as the Hebrew version of the name of Gyges of Lydia, who made his kingdom a great power in the early 7th century BC, but this explanation, although common, is not universally accepted. A different theory is that "Magog" might be a reference to Babylon, by turning BBL ("Babylon" in Hebrew script, which originally had no vowel-signs) into MGG (Magog), but this account, like the others, has problems.