Since we only have one day with Gang 104, it makes sense that a lot of them are largely defined by a descriptive title or nickname that sort of sums them up. Fetyukov is "the scrounger." He's a lot like a vulture, always hovering around trying to get something from somebody. Shukhov definitely feels a lot of contempt for him and points out how pathetic and shameful his behavior is. Unlike many of the members of Gang 104, Fetyukov hasn't held on to much of his self-respect or honor in the camp:
And then there was Fetyukov who had [...] spotted him swiping the two bowls, and was now [...] ogling the gang's four unallotted portions. This was a hint that he, too, expected a half portion if not a full one. (459)
But what exactly is so bad about Fetyukov? Isn't he like the others – trying to score for himself and to compete against others? Well, yes and no. Fetyukov does look out for himself first and foremost, like the others. But Fetyukov never tries to earn things for himself, as we see with the bowl scene. He tries to bandwagon onto Shukhov's schemes rather than take any initiative himself.
We also get signs that Fetyukov doesn't pull his weight in the gang, which is another reason why Shukhov dislikes him.
Fetyukov got lazier; the shitbag would walk along, deliberately tilting the handbarrow and splashing mortar out to make it lighter.
Once Shukhov punched him in the back.
"Filthy rat! I bet you kept the men hard at it when you were the manager!" (580-582)
Shukhov's word choice and actions here reveal a lot of genuine anger at Fetyukov, which is fairly unusual for Shukhov. He tends to stay rather even-keeled for the most part. But Fetyukov goes against all of Shukhov's beliefs and behavior, which creates resentment.
First off, we can see class commentary in the above scene. Fetyukov used to be a fancy-pants manager. He's a big-wig fallen from grace in the camps and now he acts like a lazy bum. As a hard worker, Shukhov really dislikes Fetyukov's laziness. But some of Shukhov's dislike of Fetyukov may stem from how similar they are at times. Like Fetyukov, Shukhov also tries to get extra things for himself. The way the two men go about this, though, is the major distinction between their characters. It all boils down to principles.
Tsezar was smoking a cigarette [....] Shukhov didn't ask straight out, though. Just took his stand near Tsezar, half facing him and looking past him.
That scavenger Fetyukov was there too, leeching onto Tsezar, standing right in front of him and staring hot-eyed at his mouth. (159-161)
Unlike Fetyukov, Shukhov won't stare right at Tsezar or beg. If Shukhov is a good prisoner with a blend of morals and smarts, then Fetyukov is at the other end of the spectrum with few morals, or smarts either.
But for all of Shukhov's contempt, he ultimately finds Fetyukov rather pitiful. Fetyukov has been abandoned by his family, which may account for his behavior in the camps; he's getting no help from elsewhere. And Shukhov does pity Fetyukov for his inability to take care of himself. The final time we see Fetyukov, he's bleeding and sobbing, having been beaten for scrounging around the mess hall (1078-1079). Fetyukov really shows us how far people can fall in the camps from former privileged positions and from their own sense of self-respect and dignity.