The ghouls... they appear as early as the first dungeon, they don't look scary (they look like generic trolls) but they have low drawling moans that would put the scariest zombie movies to shame.
Medusas, Vampires, and Liches make horrifying sounds AND they're the strongest enemies in the game.
If a spider paralyzes you while in the water, you will get a unique message describing your agonizing death of helpless drowning. And since you can't use potions or magic while in the water, a single spider can instantly kill you at any level if you're unlucky.
Not simply the fact that monsters roam the cities everynight causing everyone to hide in their homes, but if you break into their homes, not only are the NPCs not inside, but the houses are crawling with monsters. Meaning aside from the Inns. No-one is safe.
Actually some houses do have NPC's inside them, who seem to simply ignore the random monsters constantly regenerating in their homes.
Dungeons in Daggerfall are worse than all the Sixth House Bases Morrowind could throw at you. You're completely lost. It's past the deadline for whatever quest you went there to do. You never did find that quest item you went there to find. All you want is to find something that looks familiar and hopefully get out this damn maze. Every single door you open creaks, and all you can hear are the screams of a very angry undead thing echoing through the cavern. Somewhat sadist on the developers part, that even if you clear the entire dungeon of monsters, you'll still hear them. (Proven with the crypts in the graveyards which are barely house sized and have no more than 4-5 enemies each time)
What was worse was all the undead in the capital. They weren't scary looking, but their color made them almost impossible to see at night, when they came out. So you would begin taking damage and not know what it was.
"Vengeance!!!!" (You know it's coming, and boy is it creepy)
Not just that, but chances are if you fast travel to Daggerfall and arrive at night. The ghosts will stalk you outside of the gates and you can't fast travel out of there, so your only chances are either running away out of range, or hoping the gates aren't closed so you can escape into an inn.
The noise the skeletons make, it's a high pitched screech. You get used to it over time to the point where it's not creepy at all, but hearing it for the first time. *Shudder*
One of the Temple Quests you can get is exorcising a kid possessed by a demon. You're supposed to visit the kid in the house, he says very disturbing cryptic words about the demon. So you have to go back to the person who issued the quest and mention that. Then you get a lead about a man who knows about demon and will give you a ceremonial item that will draw the demon away from the kid and will appear somewhere in the house which you have to kill. If you get a wrong lead and don't get to the man fast enough, the kid's mother gets impatient and flees the town with her demonic hellchild. If you experienced that, it's a very heavy guilt that just 24 hours earlier you could have saved everyone.
In one cave of Morrowind, you can find several dead bodies, skeletons and a potion ingredient: Human flesh. Squick.
Corprus. A hideous disease that burns out the mind and twists the flesh, leaving the person nothing but a gibbering horror. Even worse, those infected with Corprus become immune to disease, and no longer age. Meaning there's nowayout, save by a violent death.
Some lucky few infected die from it. The description paints it as a horribly painful death.
The ash creatures. They are all creepy, but the fact that they all used to be human (well, Dunmer) as well just pushes it beyond creepy and full-on into horror.
The castle Tel Vos. Normally, it's not that creepy, but when you explore the depths you find that it's (almost) entirely abandoned and overrun with giant plants. The part that drives it home is how you keep finding diary entries from those who worked in the castle as everything went to hell. And the owner and his servants nonchalantly live on the upper levels like there's nothing wrong.
Morrowind's dungeons often contained Daedric shrines, which invariably had offerings laid out in front of them. These were always valuable objects, precious stones, weapons and such. But there is a catch: The Daedra the shrine belongs to views those objects as its own, and evidently does not take kindly to you thieving them. One of the offerings- just one- will if you touch it immediately summon something very nasty behind you.
A similar example happens in a Dunmer ancestral tomb. When exploring such tombs, at times you will come across an intact skeleton, laid to rest. Nothing unusual, these are tombs, after all. In one such tomb however, after picking some loot, one of the skeletons is awakened and attacks you. It's a little unsettling in that the skeleton is in a different room when this happens, so you'll be treated to the combat music without an enemy in sight, only to walk out of the room and find that the skeleton you just walked past have been reanimated.
In-Game book Chance's Folly. The insane warrior's betrayal of the young thief is quite disturbing, as she is sealed for the rest of her life in room with no way out. And to top it off? It's not fiction, either. Try dropping in to one of the ancestral tombs in Morrowind...
Another freaky in-game book is the innocently titled "Surfeit of Thieves". In it, a pair of thieves, a male named Indyk and a female named Heriah find a secluded castle. Told by others it is full of riches, but occupied by monks, they plan to break in. With Indyk apparently distracting the guard, Heriah breaks in elsewhere. She gets caught by one of the occupants of the castle, who asks her if she is "Lady Tressed". Going with the deception, she allows the monk who caught her to lead her back to a feast, where her partner is sitting at a table, albeit hooded to disguise himself. At the table, she notices, during the introductions from the monks, that all their names are backwards, due to an enchantment set to run out after the hourglass at the center of the table does. At some point, she hears her partner be referred to as "Esruoc Tsrif", shortly before trying to leave. However, the monks stop her from leaving, just as the enchantment runs out. If you don't understand why this story is freaky, look at the names the monks gave the thieves, and remember that the enchantment makes stated names backwards from the true names...
The Sixth House bases are generally pretty dark and creepy, first take the ash creatures previously mentioned, then add things like those giant voodoo doll looking things, bells that are capable of producing near-BrownNotes, and at least one of them features bizarre furniture arrangements that brings to mind Poltergeist.
The hulking Grahl enemies found in the same dungeons have the opposite effect but can be equally dreadful. When you first run into one you usually only see a pair of glowing red eyes and a giant, vague silhouette as it slowly walks closer to you.
Mehrunes Dagon is (one of) the world's daedric princes and leader of that army. The Oblivion Crisis is only the last time he tried to conquer Mundus, making it even worse before then, knowing an invasion could happen at any time... what's that? Elder Scrolls Online is a prequel?
The vampire dreams are creepy, and a big reason why you rarely see sleeping vampires... let's see, a normal looking woman with a child turns out to be a corpse mother, and a plague bloated child, or your flesh bubbling and falling from you... or... eating at a normal banquet that turns out to be filled with larvae, which eat through your stomach; necromancers dissecting your body with scalpels, being buried alive, death by sneezing, and having your mouth sewn shut as you try to drink from a pool of blood... creepy. And this is just text. Imagine if Bethesda actually decided to show the imagery being described...
You are told to hunt down a traitor to the brotherhood. First of all, you'll find that the traitor, in what seems to be a homage to Alfred Hitchcock's Psycho, keeps the severed head of his mother in his basement. Once found, you're told to return to the quest-giver, Lucien Lachance. However, by the time you return to him, your bosses (including the traitor) have killed him, skinned him, and hung him from the ceiling. Granted, you've seen rotting corpses in the game plenty of times. What makes this so unsettling is that you actually knew the deceased. This is made even worse by the fact that this was done by your allies. Who go on to talk about how fun it was.
The actual basement. Everything from the lighthouse keeper's reaction when you get the key to the moment you decide to leave that pit of Hell is horrifying. Part of it's the rotting, mutilated corpses—animal and human—littering the basement. There is not a square yard of space that doesn't have something grisly in it. But mostly, it's the diary you find by the desiccated and mummified head...
In-universeNightmare Fuel in the form of the Vaermina Daedric Lord quest. A wizard has turned his fortress into a literal nightmare world, filled with upside-down rooms, dark abysses, and lots and lots of detour horror rooms, particularly one that has you standing on a pillar in the middle of a vast black space filled with caged corpses and horrible screams. Trying to leave the dungeon via the wrong exit shows it situated in the middle of what looks like Hell. After trekking through this waking nightmare, you finally come to Arkved (the wizard) lying asleep on his bed near the artifact he stole from Vaermina. There are notes scattered about that imply he was at first eager and excited to explore her realm, but the last one merely reads 'I shall lie here in the dark waiting for death.' Vaermina says when you return to her shrine that Arkved 'will live out the rest of his days in nightmare' EVEN IF you killed him. Which essentially means you've killed Arkved's physical body, but Vaermina still has his soul.
If you played Oblivion on the PC and were deeply disappointed by the version of Mannimarco you meet there, a mod called "Mannimarco Revisited" is for you. With it, ol' King of Worms is back to being a scary bastard, instead of a whiny-voiced necromancer.
From the same mod, Ghostly Apparitions are light blue translucent wraiths. They have no real attacks, but what they do have is enough to give any player the creeps: they rush at you making a horrible ear-piercing shriek, until they run into your character, paralyzing them and leaving them open for attacks from other enemies. The message you get when this happens, "Ghostly Apparition paralyzes you in fear!" is probably true for the player as well as the character.
Also from MMM is the undead resurrection effect, which is to say the possibility of just about any undead monster to rise from the dead after being apparently killed without warning, and for apparently inert corpses and skeletons to come to life and attack. Good luck going through an undead dungeon without looking behind you every few seconds.
On the east coast of Niben Bay, there's a location called the Cadlew Chapel which looks like any normal chapel out of town. The chapel has been raided by four necromancers. There's recently chopped off body parts on the altar of the chapel along with a recently dead adventurer on a bloody table. What tops that though is the decaying corpse (presumably the chapel's priest) hanging from the ceiling, over the altar.
The one Thieves' Guild quest where the player had to infiltrate a certain stronghold had him or her walk through a small tunnel with the floor flooded with water. This flooded area is revealed to be a deep pit with a giant slaughterfish living in it.
There is a quest that requires you to go on a haunted ship to release a spirit. The ship isn't so scary as it is only filled with ghosts but when you reach the end of the ship, you face a wraith as a boss which keeps wailing creepily. Since the wraith was now dead, you think nothing else scary would pop up but after you release the spirit in the back room, when it vanishes, it does a noise ressembling a sudden, loud, ghastly scream.
Not to mention the quest where you have to enter Tiber Septim's tomb. It had TONS of these wraiths, and a possible glitch can cause them to not fall down dead, but just float in place as if they were alive, still screaming forever. (Happy Backtracking)
Anything and everything behind the Oblivion Gates. Particular mention goes to the "containers" used in place of standard treasure chests: mutilated torsos that, when you check them for items, make the same sound as when you remove meat from a roasted rat. They're labeled in-game as "The Punished."
That house opposite of the player's Skingrad mansion. Yeah, you're going around at night, breaking into some houses, stealing this and that? Well, you might want to skip said house, because it's full of ghosts and zombies. Who the hell would expect that?! It's in the middle of a freaking town!
It's lampshaded by NPC's saying they hear screaming coming from the house at night, also if you're high enough level there will a f***ing Ancient Lich in there! But the creepiest thing of all, the wizard who originally lived there, his fate is never explained. All we know is his house is full of zombies and he's nowhere to be found.
Sheogorath's transformation in Jyggalag. After saving the lives of either the Golden Saints or the Dark Seducers, you return to Sheogorath's palace triumphant and ready for more orders. But something is wrong. The normally jovial Sheogorath is suddenly downtrodden and solemn. When you talk to him, he has a chilling monologue about the concept of time, and reveals that he will transform any moment. Despite your pleas, he remains convinced that all is lost, and pleads with you to flee back to Cyrodiil. Just then, he doubles over and starts screeching in one of the shrillest, most terrifying voices ever, and begins bellowing in a deep, demonic voice that Jyggalag has returned. He then catches fire and starts growing taller and taller, finally disappearing in a burst of hellfire. Even Haskill is freaked out by it.
In the Shivering Isles expansion, north of New Sheoth, there's a zealot stronghold on a tall hill; inside, you go about your business mutilating them all as usual, then you find a book, detailing that people (it never clarified if they were innocent travelers or other zealots) are thrown into a very deep pit in the center of the ruins to be sacrificed to what you can only imagine to be some kind of eldritch horror. Thankfully (or perhaps not), the only thing down there are a few bollywogs, so either they're the things they worship, or the Eldritch Abomination is out elsewhere.
Since Sheogorath's main trait is to mess with peoples' heads and loves paranoia, either could be equally true.
The Oblivion Thieves' Guild quest "Ahdarji's Heirloom" has your character infiltrating Castle Leyawiin to steal the Countess' ring. During the information gathering stage of this quest, it's possible to have other characters tell you about the Countess' "secret torture chamber." Turns out? Those rumors are all true. As you make your way through the dungeon, you encounter this room,◊ which is strewn with forks, sickles, and a warhammer. But it gets worse: this isn't some Necromancer layer in the middle of nowhere; this is the Countess of Leyawiin doing this in her own castle! And even worse, it's implied that the only reason this room exists is because she doesn't like Argonians.
Even worse is the fact that she has an accomplice. The captain of the guard has a key to this exact room. Her husband treats you pretty well regardless of race, meaning that he doesn't have anything to do with it and all of this is being done right under his nose by the very people he should trust most!Think of what might happen if he found out...
Another one from Thieves' Guild is a quest, Arrow of Extrication, where you must go to Bravil Wizard's Grotto. At the bottom of the underwater cavern, if you swim all the way down through the hole at the bottom, you'll come across a Giant Slaughterfish. It comes out of nowhere, scaring living bones out of you.
If you become a vampire and you're playing a Khajiit or Argonian... there were no vampire eye textures created for the beast races, so you get the default vamp eyes. One of the creepiest things found in the game is the sight of those pale-pink human eyes in an animal face. It's remarkably unsettling.
The Daedric quests in Oblivion in general. Vaermina is probably the scariest, but a good few of them have you doing fairly horrible things. Completing all of them results in, among other things:
The Khajiit settlement of Border Watch in a panic that the world is going to end because Sheogorath (or YOU) thought it'd be a fun prank.
A group of priests of Arkay murdered in the darkness by the group of people they were trying to save because Namira took it as an insult.
A Dark Elf couple enslaved by Ogres because Malacath was feeling protective.
Said couple having been slavers themselves, the slaves having been these very same ogres.
One of the families in Bleaker's Way completely wiped out for some inexplicable reason known only to Mephala.
The only unicorn in Cyrodiil murdered because Hircine thought it would be good sport.
A paladin grieving for his dead wife corrupted because Molag Bal was disgusted by his virtuousness.
Someone from every race in Tamriel murdered because Hermaeus Mora needed their souls to divine... something.
Soul Gems. Binding a being's soul to a gem and then using that gem to drain their spiritual energy to make an enchanted item. The concept of having your soul ripped from your body and transferred to a gem, then to a weapon where your existence presumably dissolves as you power the item with your existence is bad enough. But then imagine those who don't suffer this fate and are trapped in a soul gem forever.
Oblivion also introduces us to Black Soul Gems, which exist specifically to trap human souls (which is otherwise impossible).
They wish it was just And I Must Scream, as the next game shows. See "The Soul Cairn" below for further information.
Mankar Camoran's "Paradise". While the dimension is actually beautiful (qualifying as Visual Effects of Awesome), the island is crawling with roaming Daedra which will randomly attack you and the Ascended Immortals, for whom this is apparently Training from Hell. If you think that's bad enough, there are "The Punished" chests absolutely everywhere- THEN you see the torture chamber, where prisoners and people repenting their actions end up being made immortal, chopped into giblets, and then dropped into lava- you can hear the nonstop screaming and at one point it almost happens to you!
As though Hackdirt wasn't unsettling enough as it was, try going to sleep in the inn or going underneath the town.
The introduction, where the Imperials force you to lay your head down for the axe and come face-to-face with a warm and fresh head that they couldn't bother to throw away.
The Night Mother in Skyrim. She talks through a mummified corpse. The first time you hear her speak you are shut up in her dark coffin, next to her body. If you're not expecting it this is one instance that may necessitate a change of pants.
Also related to the Dark Brotherhood storyline in Skyrim is Cicero. At first he might seem a little too eccentric and more of an annoyance than a danger. Later however, you come across his journals, written largely when he was more mentally stable back in Cyrodiil. You track his frightening descent into madness, exaggerated by the decrepit state of the Brotherhood he held so dear, his obsession over being appointed Keeper, and eternally being haunted by his final kill: a jester.
The developers of Skyrim have been critically lauded for building one of the most beautiful, interactive, vast worlds ever seen in video gaming, and rightly so. On another level however, the world of Skyrim can truly be quite nightmarish and dangerous, whether it be on the lonely northern snowfields or in a supposedly abandoned shack by the river. In its environment the game regularly generates and contrasts Nothing Is Scarier, Jump Scares, and many more tropes.
Special mention goes to the frostbite spiders. Trolls? Tough but fine. Nord zombies? Killed zombies before, no big. Dragons? Hell, those are fun to take down. Giant spider? Run. Run as fast as you can. There's even a specific "No Spiders" mod for Skyrim that just turns them into bears.
The first time you're exploring a cave and suddenly a giant frostbite spider descends upon you from the ceiling, you might need a change of pants.
And then the Dragonborn DLC introduces albino spiders, which are much smaller and more frail than frostbite spiders, but they also appear more realistic. And while frostbite spiders attack by spitting webbing and kicking with their four forelegs, albino spiders prefer to get up close and personal by leaping straight for your face.
Just north of Helgen is a place called Skybound Watch Pass. Upon entering the place, it's guarded by typical bandits, easily killed. But going just a bit further leads you to a set of iron doors. As soon as you open the doors, a giant frostbite spider awaits you, looking directly at you without any warning of its presence whatsoever. It proceeds to charge in your direction. You're also in a narrow cave, meaning you can only go forward or retreat and close the doors again until you go back and kill it.
There's a place just northeast of Markarth called Harmugstah; in said place, a mage has been enchanting the spiders.
The Black Star. Both the item and the related quest. In Azura's quest, you can get the Azura's Star we all know and love... or an utterly corrupted version, that works on Black Souls as well as white. Having this sheer unholy power is a bit on the creepy side... but the quest for it is much worse. You actually get to see INSIDE AZURA'S STAR, and meet a demented mage who's been cannibalising souls. And yes - it COMPLETELY confirms that yes — people are still aware of what's going on in there.
In one particular Dwemer ruin, you may stumble upon leftovers of an expedition that tried to explore it (not long) before you. Outside the actual ruin, the remains of a campsite contain the expedition leader's log, detailing those involvednote The leader, eager scientist-explorer; a warrior tasked with defending the group; a mage; a sorcerer; a female orc overseer, two Khajiit brothers as manual labour and a few others not detailed further and the events of their first few days, including a snowstorm that forced the group to retreat into the ruins. As you wander in yourself, their grueling story unfolds: The ongoing storm traps them inside, supplies run low, they happen upon their first Dwemer machines. A drug addiction he was attempting to hide drives one of the Khajiit mad; you find him standing over the body of his brother, and he attacks you on sight. Apparently he also slaughtered various members of the team beforehand. The sorcerer and overseer were captured by Falmer deeper down, managed to escape, but were killed by Dwemer mechs and pursuing Falmer, respectively. The mage is found dead, strapped to one of their torture racks. After you've combed through the entire place and defeated the Centurion at its end, the leader and warrior emerge and will, if left undisturbed, get into an argument over whether to keep exploring or leave this forsaken place forever, eventually starting to fight to the death. This alone would be enough for a decent horror movie...
And while the Dwemer may not be here, there is nothing to say that the Dwemer are gone. The entire affair is very vague on the details, so there is nothing saying that this incredibly advanced, astoundingly powerful and thoroughly amoral race couldn't in some way come back. After all, everyone thought that the Dragons were gone forever, too.
In the second Dark Brotherhood quest, "With Friends Like These...", you are abducted in your sleep and taken to an unknown location. You are then forced to kill one of three people (or all three) in order to be initiated into the Brotherhood. Exiting the shack, you find that it's a run-down, abandoned rat hole of a building that's literally in the middle of nowhere. For some reason the prospect of those people being kidnapped and dragged to a place like this where nobody can hear you scream or call for help is extremely unsettling.
The Falmer. They look creepy enough, but add to that the fact that they blend in with the shadows, and that odd chattering noise they make, and you've got yourself some Grade-A horror. Worse, they often appear with Chaurus, utterly nasty insectile horrors which are tough to kill, deal ugly damage with their bites, and use health draining poison that will often kill in seconds, especially if you're foolish enough to get into melee with them.
Better, there's a few areas where the Falmer are rising to the surface and have been kidnapping and torturing people. Not even above ground is safe.
"The House of Horrors" is a very aptly named quest. Let's just say that Molag Bal has gone from being a Jerkass in Oblivion and really stepped up as "Lord of Domination".
Even scarier is that you are forced to kill an priest of a rival Daedric Prince in Molag Bal's name (if you want all the Daedric Artifacts) the Priest's soul is then sent to Molag Bal, assuming for eternal torture. Remember the Wizard and Vaermina mentioned in Oblivion above? This is probably even worse, because not only is an innocent priest doomed for a similar fate, but you're the one who carried it out. College Humour said it best: "RPG Heroes are jerks"
However, the priest is not exactly innocent. His dialogue seems to infer that he had intentionally sought Molag Bal`s shrine and defiled it by using it to worship Boethiah instead. With that in mind, Molag Bal`s enraged reaction is quite understandable - he does not want priest`s death, per ce. He wants his submission - which is entirely par for the course for the Prince of Rape.
The entire backstory of the Thalmor, from their Nazi parallels to the fact that these people were somehow able to hunt down and sadistically murder EVERY SINGLE BLADE, which are made up of the best spies and assassins in Tamriel under employ of the Empire, in Valenwood and Alinor, before using their heads as a warning to the Empire, before royally kicking the Empire's ass in a devastating war.
Delphine: "Do you ever think about them, Esbern? The others?"
Esbern: "The other Blades? No. Best not to think what the Thalmor do to their victims, my dear."
A couple of quests make it very clear exactly what the Thalmor do to Talos-worshipping citizens (and more or less anyone else they don't like). However, the really nightmarish bit comes during "Diplomatic Immunity," when you get to witness it firsthand. See for yourself (though beware of spoilers).
Relatedly, what the Thalmor did to Ulfric Stormcloak. Torture is dehumanizing enough, but believing the information you gave up lost the war and rendered all your comrades' sacrifices moot? The guilt would be off the charts. Worst of all, it isn't even true - it's just Mind Rape all the more brutal for its simplicity, and all the more disturbing because it's the sort of thing that can happen in real life.
Hagravens. Witches who, through some unexplained ritual, transformed themselves into half-woman/half-raven monstrosities who are as powerful as they are horrifying. Implied to be the witch-equivalent of lich-dom, to boot. At one point in the Companions questline, you venture into a small cave populated with a few Hagravens called the Glenmoril Witches, so you remove the head of one (or the entire coven, if you wish) and take it with you in order to cure the lycanthropy of the Circle.
The quest The Taste of Death. It starts out innocent enough, the local priest of Arkay (read: undertaker priest) had to close down the Hall of the Dead in Markarth because it seems something has been eating the bodies. He hires you to go look into it. Once you go in you find it has been a woman named Eola. The woman says that you and her are the same and she hires you to clear out a shrine to Namira. You do so. Somewhat disturbing, but nothing scary, right? Well, she then tells you to go get the priest who hired you before and bring him back to "sanctify" the shrine. You get him to follow you back and it seems a bunch of other people have shown up, and they seem to be HALF THE POPULATION OF MARKARTH. Some of them you may have even helped out! The shopkeeper who took over her husband's shop? The local butcher? Yep. Cannibals. Then the woman hypnotizes the priest and has you kill him and take the first bite. So, let's see, you killed a priest, became a cannibal, ate the priest, and found out some of the friendly citizens you've been doing quests for are cannibals as well. Markarth just got a lot darker, all of a sudden.
What makes it worse is that the butcher in Markarth advertises the "bloodiest beef in the Reach." Why is this bad? Take a look at raw beef. Then take a look at human flesh and try not to wonder if that's really beef...
That shopkeeper who took over when her husband died? She says this when you talk to her during the, eh, meal: "One of my customers? Did you know I inherited the store from my late husband? Shame what happened to him. He had such good taste." Either she has a very dark sense of humor, or her husband was a cannibal as well, or she ate her husband. Or perhaps all three are true.
The Ratway Warrens. Highlights include an insane deaf woman who sits in darkness endlessly repeating a list, a cannibal chef who wants to make a meal of you, and a PTSD suffering ex-Imperial Officer who mentions some horrors that the Thalmor did.
"Their fires lit up the night. All across Lake Rumare, like stars come to earth. It was beautiful, really."
One that's thankfully easy to miss is found in one of the Dragon Priests' tombs. Said priest was a crazy bastard even by the standards of insane dragon worshippers. He had his followers commit mass suicide so their ghosts could continue to defend the place. The truly disturbing part? He apparently sacrificed children to make this work. You can find an open grave full of small wrapped bodies in the tomb. On the plus side, it makes killing this particular Dragon Priest that much more cathartic.
Every step in the murder mystery of Morthal. Especially the part when you play hide-and-seek with a child's ghost. The moment you find her at her grave she recoils in shock because a freaking vampire lady shows up right behind you.
One of the earliest Companion quests is to sort out a trouble-causing Falmer group in Shimmermist Cave. In the end, you find the leader. He was in the middle of the room, so you can back him up into a corner by using Fus Ro Dah. He slammed into the dark wall... only for the wall to walk forwards and reveal itself to be a huge Dwemer centurion.
The Dovahkiin is, in his/her own way, a walking Mook Horror Show just waiting to happen. Just imagine that you're sitting in your camp, on watch for a caravan or some roaming monster or a military patrol that might fall upon the home you've carved out. It's the dead of night. Then, coming up the trail, you see a single person, alone. They're wearing nice armor and wielding a nice weapon, but they're by themselves. Easy prey for a dozen bandits, right? That armor and sword will make for a great haul! And even better, they're walking right toward your camp! You call your buddies, and they ready the ambush, and just as you leap out to strike, you hear "FUS RO DAH!" The next few minutes is a horrifying blur as you and your companions throw everything you have at this lone warrior, while lightning and fire and demonic beasts and even a freaking dragon comes swooping in and around you. You companions are being torn apart, blasted to ashes, or decapitated one by one, and this unstoppable warrior just keeps coming, periodically shouting out blast waves at the top of his/her lungs and moving impossibly fast, striking with terrifying precision, hurling armored warriors through the air like feathers, or just making people keel over and die.
Dawnguard ramps it up to eleven with the ability to shout and rip out a person's soul and raise them as an undead thrall, if that isn't enough you can summon an undead dragon for fun... and while the werewolf form attacks are brutal, the Vampire Lord form is pure nightmare fuel. Around 8 feet tall, built almost as sturdy as a troll, the Vampire Lord simply glides around while either draining your very life essence or raising your buddy as an undead thrall. Oh, and if you survive his magical onslaught? He lands and proceeds to introduce you firsthand to his claws which are every bit as brutal as a werewolf's.
And all of this is just peaches compared to how the dragons themselves see the Dragonborn. This is a mortal with the ability to take the souls of any dragon he or she kills, using them to unlock dragon shouts and new ways to bring utter pain upon them, before stripping the very bones from their corpses and forging them into weapons and armour to further mock their kind with.
Mirmulnir's last words definitely sum up the horror a Dragon must feel when encountering the Dragonborn. For most of the entire battle he's incredibly confident, as with Alduin back, not even death could stop him for very long. But then you see that sense of smugness quickly dissolve into unbridled terror as he realised far too late just who the person standing in front of him was. Imagine spending your last few seconds feeling your skin begin to catch fire and your soul rip itself away from you. No wonder he screams.
Miraak: Do you ever wonder if it hurts, having your soul ripped out like that?
Dragonrend and Bend Will. The former is weaponised nightmare fuel for Dragons and the latter makes them slaves to your every whim. Are you still sure you're the hero and not the real monster of this story, Dovahkiin?
Don't forget how he might seem if you leave the Civil War questline til last, after the DLC and decide not to hold back during the fort assaults. The soldiers fighting alongside the Dragonborn may as well not be there as he walks in; armoured in the bones and scales of dragons, wreathed in the spectral armour of the Dragon Aspect shout as a dragon roars overhead before swooping in to fight alongside him? Just seeing this guy calmly walking up to the fort should have the whole place on the verge of surrender.
The Maze of Shalidor. It is in an non-important place in the Labyrinthian zone, and is not connected to any quests. It is basically a maze where you have to perform one spell from each school of magic. And how's that scary? Well, when you have made all spells, the underground cave opens, and there is a portal. You step into the portal, and are transported to a weird purple circle, where you have to fight a dremora. It is explained in a book that Shalidor made it as a test for potential archmages. That's why it requires knowledge of all spell schools and enough power to defeat a powerful Daedra to survive it.
Hermaeus Mora has always been really creepy, what with the way all of His artistic renditions have depicted Him as a formless Eldritch Abomination. But in Skyrim, you don't even get that when you meet Him face to face, as it were; what you get instead is this swirling black vortexthat appears out of nowhere while you weren't looking, blocks your only exit, and speaks to you in an affable and beguiling voice. Mora's been watching you, and He intends on making you His new emissary, whether you want it or not.
And in Dragonborn you get to go to his real Apocrypha, filled with all sorts of Lovecraftian horrors. Enjoy!
And if you didn't think his appearance in the vanilla game was bad enough, if you download Dragonborn, his appearance changes to a series of voids that have tentacles coming out of them and eyes that appear and disappear.
Astrid's body at the end of "Death Incarnate". She's burned all over and practically skeletal, and everyone, especially she, knows that she's committed an unforgivable sin (by Sithis's standards, at least) and she has only seconds to live.Alas, Poor Villain, indeed.
With the addition of the Dawnguard DLC came the Soul Cairn, a plane of Oblivion to which human souls that have been captured in black soul gems are sent after the soul gems are used up. The piles of bones everywhere are to be expected of what is essentially a graveyard dimension, but the true horror is the fact that all of these souls are in a permanent And I Must Scream state. If you talk to any of the unnamed souls, they will occasionally say that they feel like they are constantly being drawn and quartered...
You know, as terrifying and icky and creepy as the chaurus are, you've at least got the reassurance that you can outmaneuver them and keep out of range of their horrifically-powerful bites. Noooooooooope. Not with Dawnguard! Now you have to deal with Chaurus Hunters. The Chaurus Reapers? Those were the larval form. The Hunters are massive, winged, mantis-like creatures with stingers. It's basically a Chaurus Reaper except even tougher, and it can fly.
To add to their vileness, they don't simply hatch from cocoons like butterflies. Instead, the normal chauruses (chauri?) are the cocoon, and the hunters burst out of them chestburster-style. Sweet dreams!
It does not help that chauri look suspiciously like another kind of Reaper, only (barely) shrunk down to melee combat size.
Now look at some construction materials of the Falmer huts. They get bigger...
Shellbugs are harmless, but they can take a player completely by surprise. What may look like a giant boulder or even a tent quickly turns out to be a pill bug-like insect roughly the size of a flatbed truck.
Dawnguard also adds the Castle Volkihar tower leading to the Soul Cairn, at which point the game essentially becomes Dark Souls lite. You're making your way up the dark tower, which only has about 3 healing potions in it, fighting very high level skeletons, in addition to a few death hounds. But the worst part is when there are no skeletons, and you're wandering around the shadows, wondering which of these gargoyles is going to come to life...
Dawnguard also adds Darkfall Cave. A completely pitch black cave full of trolls, the aforementioned Chaurus Hunters, and Frostbite Spiders. Early on in the cave, you come across a thin, rickety bridge spanning a ravine with a rushing water current at the bottom. The bridge creaks rather ominously as you pass over, but nothing more. On the other side, you find very little and proceed back across... Only for the bridge to collapse and plunge you into the dark abyss. You're left at the mercy of the current as it sweeps you through narrow fissures and out into a large cave with just enough light to see several massive Frostbite Spiders falling from the ceiling.
Darkfall Passage may be worse. The primary light sources through most of it are glowing pink flowers that retract when you come near, leaving you in darkness. In addition to the Falmer running around, you have chauri, including several hunters and hunter fledglings, hidden in the carcasses of dead ones that you don't notice until you step on them and they burst out and you can barely see them in the dark as they're flying around you, so they're hard to hit.
And then there's Darkfall Grotto, which gives us Feral Falmer, who are a naked, blood-splattered, more animalistic variant of Falmer that kills their own kind.
Dawnguard is just a treasure trove of nightmare fuel. The first time you walk into Castle Volkihar deserves mention: the vampires are in the middle of a feast, with bones, gore, and spattered blood contrasting with the otherwise luxurious surrounding. There are even human corpses laid out on the tables, and a few of the vampires are chin-deep in their entrails like children in their first birthday cake. Imagine literally walking into the middle of that, completely surrounded, the only human present. Oh, wait. Those corpses on the tables? THEY'REALIVE. On the plus side, science has proven that this makes it at least 100% more satisfying to storm the castle and have a whingdally of a slobberdocker on the vampires with a big ole' axe.
In the Dawnguard add-on, if joining the Volkihar Vampires, you may be sent on a quest to recover a petrified ancient vampire's HEAD. Sweet dreams.
In one quest where you help out a struggling shipping company against pirate raids, you must storm the pirate's fortress, Japhet's Folly. If you explore a bit, you find a locked room in which you find the corpse of Japhet himself, along with his journal. Reading it, you learn the history of this place. Japhet writes of leaving Dawnstar with a crew to build the tower, but his crew left one by one, convinced that the place was haunted. Soon, Japhet was left all alone. He eventually becomes convinced that the ghost stories were true, as he hears them speaking to him. A little creepy, but nothing too severe. What clinches it is that Japhet seems like a fairly normal, stable person, until you turn to the last page, which simply says... OH GODS HELP ME
The quest in Frostflow Lighthouse. You enter the lighthouse to find furniture overturned, with blood everywhere and a dead body. Your quest message flashes across the screen: find the murderer. By reading the journals, you find that it was the couple's dream to retire to a lighthouse, even though their mostly-adult children didn't like the idea much. They've been hearing noises in the cellars, and assumed it was just skeevers. Then the husband comes home from a shopping trip to find his wife dead and children missing, and locks himself in the basement to either kill whatever did this or die trying. Turns out the cellar opened up into a large ice cave swarming with Falmer and Chaurus. Along the way, you find the rest of the family members' bodies - the son being the first body you find, the daughter having killed herself to escape the horrible things the Falmer did to her father and others they dragged down there, and the father's remains being inside a Chaurus Reaper.
Oh yeah and you see those Morrowind examples above, about the ash creatures and the other horrific monsters in the game, yeah now they're back in full unholy HD.
The first encounter with Miraak can be really disturbing, after going down to the depths of his tomb, which is ominous in itself with how large and deep it goes and the Lurker heads and Dragon skeletons along the walls, and you find a mysterious book. Upon reading the book, you are grabbed by tentacles and appear in a strange dimension where you are discovered by Miraak and a couple of Seekers who quickly incapacitate you, and after giving a speech he leaves on his dragon for the Seekers to "send you home" (which in this world, is by virtually killing you).
Encountering a Lurker can be really damn horrifying your first time. You will usually either encounter them in Apocrypha where they rise from a pond of black liquid, when you use the Bend Will shout on the stones, releasing them, or just along the shores of the island where they can appear out of nowhere. They are nearly as tall as giants, and hit nearly as hard. All of their melee attacks can stagger you, and even at a distance they can still hurt you by throwing balls of tentacles. Not to mention they are fast for their size. And may the Allmaker help you if you encounter more than one at the same time.
The Stones themselves before being cleansed can be pretty ominous, with a group of people working on some kind of structure while reciting a strange mantra. And if you touch the uncleansed stone or sleep you wake up to find yourself working on the stone, while Miraak ominously calls out to you.
The fact that everything you do in the main story of the DLC in some way helps Hermaeus Mora, which depending on your character, can be anywhere between an Unwitting Pawn to an Anti-Hero. How he kills the leader of the Skaal and Miraak is also pretty horrifying, impaling them with tentacles while giving them a "Reason You Suck" Speech, with a very guttural voice. It almost gives off the feeling that no matter how powerful the Dragonborn has become, (s)he is still no more than a pawn to the Daedra.
Oh, it gets worse than that. To elaborate, Hermaeus Mora spears the Skaal leader through with several tentacles, including one through his brain, and proceeds to have a cruel conversation with the horribly suffering and very much conscious man. And then, when he has what he wants, Mora just shakes the man off the tentacles and disappears, leaving the man's daughter to exclaim in horror over her father's dead body. Yep, she was watching the whole thing. Imagine seeing that happen to your father.
Note that Hermaeus Mora isn't necessarily in control of the Dragonborn by the end. Although you end up helping him/it in some ways, the Daedric Prince isn't as omniscient as it leads one to believe, and is fully capable of misleading people. For one thing, Mora implied that the Heart of Lorkhan was inside of the locked Dwemer room that Septimus wanted to enter, which really contained Mora's book of knowledge (the Oghma Infinium). On top of that, we have a supposedly all-knowing being needing your help to get knowledge from the Skaal, something that an omniscient entity would not have to do. Next, we have the fact that the Master Telvanni Wizard Neloth says that there's none of the documented signs of Daedric control present in the Dragonborn, such as black spots in the whites of one's eyes. Finally, the Elder Scrolls games as a whole have been mostly oriented against fate as being absolute and unavoidable. Examples of the series' emphasis on free will include the time the Hero of Kvatch was able to break the Greymarch (which was said to be preordained and repeating once every era), when the dragon Paarthurnax explained that prophecy was only what may be, not what must be, and the fact that Elder Scrolls themselves only become fixed in their writing after the event written on them has come to pass. The only two major sources that speak out in favor of fate as being absolute and preordained are Hermaeus Mora (who is misleading at best), and Azura (technically, a priestess of hers' says this). So basically, while Mora might have been helped by the Dragonborn, it isn't clear that he's really pulling the strings.
A little and horrible (but very easily missed) detail: The Words for any other shout are almost always carved on rock, as the Word has to actually be seen by the Dragonborn in order to learn it. Well, the third Word for the Bend Will Shout is acquired immediately after The Skaal Leader dies and there is no Word visible at the time... or so would you think; the Word for it is carved ON THE DEAD LEADER'S CHEST, briefly giving off a faint green/orange/yellow aura, compared to the blue/white that normal words emanate
It's safe to say that the entirety of Dragonborn's main story is this, it's like The Elder Scrolls meets HP Lovecraft. Which Bethesda has done before in Oblivion (A Shadow Over Hackdirt) and Fallout 3 (The Dunwich Building); we can easily say Bethesda really really loves Lovecraft.
Though after the first few times you can get desensitized to it, the first few times you raid a bandit camp/fort can be this when you see what they've done to the people they've captured. It's not uncommon to find bodies in locked cells, or in a few cases you can find bodies on tables where they were cut open and tortured. Which just makes slaughtering said bandits all the more satisfying when you finally get to do it.
And then in Fort Greymoor you find an old woman who's not hostile to you and just states that she just cooks and cleans and does whatever the current occupiers ask her to do. Some of her lines are downright chilling when you think about the things this woman must've seen:
"I remember one morning long time ago, I woke up and the place was run by some Orcs. Went to bed that night, it was all vampires. Don't matter to me."
And necromancer hideouts, which often contain desecrated corpses, often in pieces.
Speaking of necromancers, in two major dungeons, you encounter some really nasty pieces of work who have found a way to enslave ghosts.
Rannveig's Fast is home to Sild the Warlock, a necromancer who has taken to luring adventurers to the ruin so that he can kill them and enslave their ghosts to his will. You encounter these ghosts as you're heading through the Fast, and when they sight you, they will attack you, but their dialogue as they do so makes it very clear that they are being forced to do this against their will, suggesting that they are fully aware of what is being done to them.
Yngvild is home to Arondil, an elven necromancer with a lustful obsession with the women of Dawnstar. Like Sild, he has found a way to enslave ghosts to his will, but unlike him, he prefers to create these ghosts from the women he lusts after, whom he has his draugr bring to him, so that he can basically turn them into unliving Sex Slaves, with all the disturbing undertones one can expect. And that's not even mentioning what he did to the draugr (who in this particular ruin were all female) after first creating them. Sneaky players can steal the soul gem he uses to maintain his control over the ghosts for a veryKarmic Death.
An ingame book, Physicalities of Werewolves, deals with a researcher's morbid study on live werewolves. It describes the experiments on two subjects, A and B. It starts of relatively innocent with A, even though he eventually dies as well. It's with subject B that things get nauseating, as the researcher performs vivisection on her. In other words, he cut her open while she was still alive and then forced her to transform so he could study the effect the transformation had on her organs and muscles. The subject was still very much alive during all this and before she could succumb to her wounds, the researcher applied "remedies" for the disease directly to the internal organs. The Wolfsbane rendered the subject's bones brittle ("the ribcage nearly collapsed at the touch") while some sort of berry juice was pressed directly into the veins, which caused them to "shrivel behind the flow as it moved through the system. Upon reaching the heart, the major vessels pulled away completely, and the subject expired within minutes". Holy fuck. You can find this book on some members of the Silver Hand, which pretty much adds to their general unpleasantness due to their penchant for torturing werewolves that they get their hands on.
The moment when you find Meridia's Beacon. So you stumble across a chest and find some goodies as well as some weird prism. "Hmm? Never seen anything like this before..." You take it out, close the chest, and are immediately treated to one HELL of a Jump Scare by this otherworldly voice commanding you to return the beacon to her statue. Mercifully, Meridia is bar none the nicest of the Daedric Princes, but she's still downright terrifying when she wants something from you.
The Forsworn. While they may have some legitimate grievances against the Nords of The Reach, they are still very much the brutal savages that the residents of Markath make them out to be. They worship Hagravens, who return the favor by ripping out the hearts of chosen Forsworn to turn them into quasi-undead Briarhearts through a dark ritual. At one point, at one of their hideouts, a Forsworn can be seen at a sharpening table with the corpse of a Nord nearby, happily commenting that he's going to turn the Nord's skull into an axe head.
In one quest, Sanguine gets you drunk which you did a lot of crazy things during the night, like stealing a goat, making out with a statue, and proposing marriage to a Hagraven which she accepted. When you meet up with her she is very happy to see you calling you "My love"; usually Hagravens are always hostile and as far as anyone is concerned, incapable of love or any pleasantries at all. The game doesn't tell you "what you might have done that night" to gain her approval. What may or may not have happened, don't think about it too hard. Please.
East of Riften lies the "Lost Prospect Mine", where a journal is in the entryway detailing how a couple of miners had tried refreshing it, but it seemed to be tapped out. The author of the journal went to Riften to get supplies and cool his head, and when he returned, his partner was nowhere to be found. If the Dragonborn uses Whirlwind Sprint, the skeletal corpse of the other miner can be found buried hip-deep in a landslide... meaning that he'd died of thirst, starvation, or compression, rather than a quick death.
In White Ridge Barrow on Solstheim you will encounter bandits who are being controlled by an Albino Spider variant that adheres to their necks and covers their skin in some glowing light green web.