He was 5’7" in height, appeared to be about thirty years old, and has a thick drooping moustache. Otherwise he was totally bald. He wore a gray uniform of thick material, as well as long boots of tanned hide. He also wore a fur hat with a silver star in the center of it.
Major-Commissar Gregori Zimyanin was a member of the Russian Security Bureau (sort of an amalgam of the KGB and the army). He appeared multiple times throughout the series, opposing Cawdor's team.
He was the leader of a patrol of Russian soldiers who were hot on the trail of the Narodniki, a band of bandits and marauders. After finally catching up to the group only to see nearly all of them killed when J.B. Dix destroys an ancient dam, he confronts Ryan and his band. They negotiate a deal on who gets to kill the surviving prisoners. After which, Zimyanin attempts to claim Alaska for Russia, but Ryan’s band refuse, pointing at a dummy missile, threatening to use it against the soldiers. He takes the bluff and returns to Russia with his soldiers.
Zimyanin later discovers Ryan's band deep in the heart of mother Russia, after following their exploits for several days, he and a band of his soldiers finally encounter the band of friends. He chases them right into the gateway and is forced to jump with them. In the first redoubt they jump to, the Major is forced out into a control room where he encounters some sort of huge mutant, which is never truly seen. Several shots are heard and a scream but it is not revealed if he is killed or not. This takes place at the end of Red Equinox, and the beginning of Northstar Rising.
Somehow he managed to survive the mutant's attack and escape the redoubt. He since that time took over control of a sulphur mine. Over a period of months, he learned to use the redoubts, and discovered the LD or Last Destination function and used the redoubts to bring slaves to the mines. He and Ryan destroyed on of the sec hunter droids Ryan activated accidentally, and ended up falling to his death.
He was encountered for a final time in Chill Factor, where he was killed.
He killed himself after a plot to kidnap Ryan Cawdor's son because he was too honourable to allow a small child to bear such a heavy grudge.