Nick Moreau is what you could consider a CIA agent. Initially, not much is known about him. However, those who managed to get close to him and survive the help for him in certain missions can tell he is some sort of imperialist with some hate to communists.

Nastasia/Nautilia was a Zerg Larva that for unknown reason was adopted by Stukov himself. She became unique due to herself infesting local aquatic wildlife. Her present looks is thanks to the fact she conjoined with a human and Protoss corpses she found greatly deep underwater.

(Zerg belongs to Blizzard)