We have a whole slew of antagonists here, the bulk of whom are nameless "guards" and "wardens." These are the men who enforce the rules of the camp. Throughout the day these men yell at the prisoners, threaten them, throw some of them in the "hole," and otherwise make life miserable for everyone. But these antagonists aren't just wholly evil. Shukhov himself even notes that the guards aren't exactly living the good life in their jobs either. In a way, the camp itself is the main antagonist, or the system that keeps all these men stuck there in bad conditions. If we had to pick one person to go with as our chief villain, we'd go with the evil disciplinary officer, Lieutenant Volkovoy. The dude carries a whip around after all, and he's basically the epitome of the mean and sadistic prison guard who use their position of power to torment others.