Ndrog was the last of an ancient race of giant germs from the Dimension of Doom and was solely responsible for wiping out at least half of that dimension’s population. He attacked the ship Iceworld, infecting the young Andor pilot Kdreegs Dhuds. He was able to get no one else, however, as the suspended animation started up and froze them. Furious, he programmed the ship to generate too much ice, killing them all. He himself survived thanks the frustrating resiliance of germs.
When Michael Peterson and 2-Tor came to investigate, Ndrog attacked and infected the poor little droid. Michael volunteered to be infected and take Ndrog to Dimension Q, but it turned out that although Ndrog was impervious to every known weapon, the beings from Dimension Q were poison to him. His previous Andor host had invited the two heroes to destroy the germ just before becoming infected.