Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Oz
It is never a good thing when this guy shows up...
Here be the Nightmare Fuel page for Oz. With examples like the following, it is not at all hard to see why this show was one of the most disturbing of its time.
Tobias Beecher's entire stroryline. Sure, all the inmates suffer, but he is the character people would sympathize with most, because he is vulnerable, tries his best to stay sane, and goes through so much. All through season 1, you watch a respectable man (a lawyer, how ironic is that) being sent to jail, getting raped and humiliated in many ways by a nazi who threatens his family, and who wants then to have him dead. Beecher's breakdown is both awesome and terryfying, because of what the jail turned him into. And it worsens in later seasons: his wife kills herself, his children are kidnapped, one of them and his father are killed, he loses his chance to leave Oz, and falls in love with a manipulative serial killer, who commits suicide to get him charged with murder and possibly put on death row. You'll see few to no episode where Beecher doesn't suffer in some way.
The season two finale, which is jam packed with High Octane Nightmare Fuel:
What happens to poor Luke Perry (being bricked up behind a wall and then burnt beyond all recognition afterwords when a gas leak explosion ends up freeing him) in particular was very nightmarish.
Reverend Cloutier, who is sealed inside the cafeteria wall by Timmy Kirk and the bikers, remains there forgotten for what must be at least several days, is caught in an enormous gas explosion, survives, sustaining horrifying burns, then as his throat begins to recover so that he can almost produce more than a raspy gurgle, the bikers pick up his charred body and brick him behind another wall to keep him from naming names. As if detaching him from life support wouldn't have been enough. Father Mukada finds his decaying corpse in the final episode, only to seal it back up, figuring he's better off left where he is.
And remember this guy was only in prison on a charge of embezzlement. Serious crime, yes, but what a cruel fate to wind up alongside serial murderers who rape and torture people for fun.
It is revealed late in the series that despite Cyril O'Reilly's brain damage, he sometimes has the abstract thought of his former self. But it seems impossible for him to communicate in an intelligent manner, as if he's trapped inside of a five year old instead of having the mind of one.
Schillinger. Holy shit, just about anything and everything involving him qualifies. And of course, the Aryans. Robson comes to mind, but only in the shit he endures as a side-effect of his own assholery (having the tip of his penis bitten off, a spoon rammed up his ass, not to mention the subplot with the dentist).
Ryan's obsession with Dr. Nathan.
Timmy Kirk takes a woman's baby from her, and proceeds to place the crying infant in a nearby dumpster filled with rats while the mother is forced to watch, horrified beyond belief.
Reverend Cloutier confirmed it was Kirk's own baby he was dumping. I think the child survived the experience, but Timmy just got scarier as the series wore on.
It was his, as confirmed by Reverend Cloutier. We're never told for sure whether the child survived, but we do know that he was originally sent to prison on charges of manslaughter and endangering the welfare of a child, with a sentence of 12 years. Given how intentional his act was, I find it hard to believe it wouldn't be considered at least second degree murder. So it's possible that the manslaughter charge referred to him doing in someone else, but if so, we never found out who.
Adebisi, even when he's not being evil.
Ryan and Chris at times. Plus their tendency to manipulate people, use them, and how you can never completely tell if they are good guys or bad. Or what they're planning on doing next.
The nightmares that many of the inmates have while in prison.
Of all the gangs, the Christians are arguably the most psycho and nightmarish of the gangs. Despite their seemingly saintly and non-violent nature, they are the epitome of Light Is Not Good and Corrupt Church. Their members are usually guilty of the worst crimes, mainly sex crimes or crimes against children. Only two Christian imnates don't fall into this category and one of them is an Anti-Villain who dies a horrific death. Arguably the most creepy thing about them is that they have an utter lack of self-preservation, to the point of becoming death-seekers.
The disturbingly realistic portrayal of drug addiction, alcoholism, sexual abuse, rape, sadism, torture, bullying, suicide, murder, etc. Makes one want to avoid even entering a prison at all costs.
Even scarier, some death row inmates have claimed in interviews that the prison experience depicted in this show was BETTER than life in a real prison, saying that this show was cleaned up for television. HOLY SHIT.
How the hell could it be WORSE? Dear God.
The fact that the Aryans target the most vulnerable inmates and make them their sex slaves, for as long as they want, until they grow tired of them and just dispose of them. And the terrible truth that the inmates would have to endure that cruel and humiliating treatment for the rest of their lives. A few did deserve it... Still...
While Adam Guenzel was a piece of shit rapist, it doesn't make the rapes he endures at the hands of the Aryans any less disturbing. His anguished protests for them to let him go are what got me shivering.
Winthrop: "Sir? May I watch?"
Schillinger: "Well if you don't, how are you ever gonna learn?"
One word: Robspoon.
Robson and another Aryan killing Ahmad Lalar, the youngest and weakest of the Muslim 'herd' just to prove a point to Said. They slice him to death by repeatedly making shallow cuts with a knife, while Ahmad's screams are muffled by his gag and he (as well as we, the audience) can only watch this horrifying scene.
Beecher's long nails that he deliberately does not cut while in the hospital and files to razor sharp points. Which he then uses to kill Metzger by slicing into his body, making huge gashes and leaving the unsavory guard to slide down the wall while he claws at his mutilated throat, trying desperately to stop the blood from spurting out and failing miserably before dying in a pool of his own blood. Horrifying doesn't even begin to describe it. Granted, Metzger had it coming.
Chucky Pancamo tying his girlfriend up in a body bag and throwing her into the river. While she's fully conscious.
Nino Schibetta ate grounded glass that Ryan and Adebisi secretly put into his food for months until he dies from internal hemorrhaging, suddenly realizing one day that he's bleeding from the ears, nose, mouth,...
One of the prisoners throwing a "blood-piss-puke-shit-cocktail" at a CO and another one smearing something similar on Peter Schibetta's face when he was in psyche ward.
looks more like finger-paint to me in Schibetta's case, as I haven't yet seen a bodily fluid that yellow (at least not one that can be produced in those quantities by a healthy human)
Beecher's little son being killed and his cut off hand sent to him into the prison...
When Schillinger's loyal right hand man, Robson, is found that his gum implants came from the mouth of an African American, he is immedietely cast out from the group. Desperate to return, he uses a shiv to PEEL OUT HIS OWN GUMS. Unbearable — here, have some Schmuck Bait. http://www.youtube.com/watch?v=Ti5fTPsdIOA
Aryan's interaction with Cyril when he first came to Oz. And then Schillinger's gleeful expression before him and the Aryan's gangraping of Cyril didn't help things either. This was one of the things responsible for Cyril's downward spiral that led to him being put on death row later just made that scene unsettling.
In the sixth season a production of Macbeth is being put on by a number of prisoners with Schillinger in the lead role and Beecher as Macduff. Keller takes a job backstage managing the props. He tells Schillinger that they will kill Beecher then later tells Beecher that he is being friends with Schillinger to keep Beecher alive. He then kisses Schillinger and tells him that he will switch Schillinger's prop knife with a real one so he can kill Beecher onstage. However, during the final fight scene, Keller switches Beecher's knife with a real one. Beecher stabs Schillinger unintentionally during a fight scene, thinking the knife in his hand is a prop. Keller claims to have no idea how a real knife got onto the set. Schillinger's death is considered an accident.
Really the entirety of the Macbeth play storyline. Keeping in tradition of Macbeth being a cursed play, all the inmates who take on the title role die.
Initial Macbeth Father Daniel Meehan is cursed by Peter Schibetta and dies of an aneurysm in his sleep.
Schibetta is killed by Chucky Pancamo after O'Reily tricks him into thinking he will be the next cursed.
Wolfgang Cutler accidentally strangles himself attempting autoerotic asphyxiation.
And then Schillinger.
You might also consider all the deaths in the final season a part of this. Said, Glynn, Morales, White, Hoyt, Cyril, Schillinger, and Keller were all main characters who were died. Did the Scottish play bring death to all those we loved and hated?
Richie Hanlon has just come off death row and returned to the general population. First night back, he's in the shower when another man starts coming onto him. Both Richie and the audience are expecting some celebratory "off-death-row" loving, until the other man slits Richie's throat with a razor blade he had hidden between his teeth.
Shillinger telling Beecher "You belong to me. I make all your decisions."
The life of prags (sex slaves) in Oz.
The numerous rapes and attempted rapes.
One inmate kills himself by eating pieces of himself.
Peter Schibetta's downfall.
Dino Ortolani's death in season one (being burned alive while not able to do anything about it)