Sergeant Nak (called Big Green Hairy Guy in the official volume VIII cast list) is a gigantic furry green monster first seen under the command of Captain Vole. He gives the definite impression of being impressive muscle for their mission of bringing Gil to safety whether he wants them to or not. However, this impression is quickly proven wrong, as he turns out to be the squad's Sergeant, and apparently a rather conscientious one given his .
After Gil disappears following his handling of the War Stompers, Sergeant Nak moves to where the Baron is recovering. He welcomes the Quester Grantz with a hint of envy or admiration, while he gives Sergeant Scorp a bit of a hard time.
Sergeant Nak has been described by Grantz as a ; what this means when applied to a green-furred monster whose eyes are hidden behind orange lenses might be unclear had it not been for his reaction to Sergeant Scorp in the preceding panel. The orange lenses are apparently cybernetically fashioned to his head and automatically adjust to different objects to compensate for his severe nearsightedness.
He is also the head of the Wulfenbach military forces aboard Castle Wulfenbach, where the Baron tries to encourage Nak's kinder impulses; in particular because his usual considerate-to-a-fault nature only seems to make others more worried.