The Macellarius are just disgusting to look at, being grotesquely swollen and obese — and they just get fatter as they age. They seem to be so polite, so genial and then, when you least expect it, they snap at you like the beasts they are. They hold the most disgusting banquets you could ever imagine, which sicken even other vampires — and that's before you take into account the fact that they can actually eat human flesh, and invariably become addicted to the taste of it.
The Carnival are a Daeva bloodline who are so prone to Body Horror, even if they were perfectly normal before the Embrace, that they actually get the Nosferatu clan weakness. Out of the sight of ordinary humans, they perform the Show, sights and acts so bizarre that the most depraved human freak show could only dream of it. And if you're lucky, you'll be drawn into a special performance... The Carnival calls that "the Blowoff", and it's how they find prey.
The Oberlochs are basically the antagonists of every Hillbilly Horrors film come to (un)life as clannish, weirdly incestuous vampires. They're savages, they absolutely hate "city slickers", and because of some weird quirk of their blood, they're eternal but they still age. Expect re-enactments of the famous "sucking on bloody fingers" scene from the original The Texas Chain Saw Massacre (1974).
The Sangiovanni are incestuous, necrophiliac, inbred mafia necromancer-vampires.
Let's save time and state that most of the Nosferatu bloodlines are this, but, if really curious...
The Burakumin are unnervingly, unflinchingly polite... but their take on the Nosferatu curse means that as the years roll by, they keep rotting away. Oh, and did you remember they happen to be one of the three Bloodlines that have Disciplines that let them create and commandThe Undead?
The Noctuku are monsters even to other vampires; they are plagued by an insatiable craving for not only the blood, but the flesh of other vampires. They're actually a Mythology Gag to the Niktuku of Vampire: The Masquerade, who were similar in nature. Oh, and it's hinted that any Nosferatu who indulges in diablerie could become one of them.
The Rakshasha are so deformed and naturally malevolent that they believe they genuinely are demons sent to torment all who live on Earth.
The Moroi might seem like a mild example. Oh, sure, they have in-clan access to two of three physical disciplines, and the stealth discipline, and Animalism, and probably start with dots in either Nightmare or Protean with easy access to the other, and they either hunt in packs or are old and powerful enough to take on entire coteries alone, and they have murderous impulses, but they probably won't physically or mentally torture you for decades like your average vengeful Ventrue—though they might deliver you to one after painfully subduing you. Nope! If you cross them, or you're their assigned target, or you get in the way, or you learn too much, or you happen to be wandering down the street when they're hungry and one of them lacks the self control to not drain you dry, they'll just kill you. From the shadows, probably quicker than anything short of a werewolf could survive long enough to fight back. Nothing to worry about at all!
The Brothers of Ypres, a Bloodline that mutated from a vampire who decided that the gas attacks in World War One were the ideal time to feed. They wield the Discipline of Asphyx, mentioned below, which lets them create mustard gas from their blood. They can poison you with a touch, they can exhale gouts of it over you, they can even turn into living clouds of the stuff. Read up on what mustard gas does to a body, and be afraid. Then remember that the Brothers can only feed on blood that is contaminated, that they have stockpiles of chemical and biological weaponry, some even have nukes... and then be truly afraid.
Formosae: They're like vampires, but not quite vampires. They deliberately prey on people with poor self-image because they feed on resentment and loathing; their feeding does drain away fat and leave their victim beautiful but it quickly becomes fatal. And they are themselves absolutely hideously fat.
Cymothea Sanguina: a parasitic arthropod that bores into the lower jaw and eventually replaces the tongue, slowly converting its human host into a mindless blood-drinking zombie whose guts eventually rot away and fall out (to nurture larvae), leaving them to spend their last few days alive savagely attacking anything in sight.
The Ragged Man is a parasite that grows inside vampires, sort of a repulsive combination of a tapeworm and a Chestburster.
Draugr are what happens when a vampire finally gives up on trying to maintain some level of humanity. Larvae are vampires who were made that way.
Even worse are revenants — Larvae are at least mindless, and if elevated into true vampires don't remember what they did as animalistic near-zombies. Revenants don't even have that, they just rose from the dead one day without any idea of what they are, constantly starved for blood, all because some Jerk Ass true vampire didn't care to avoid killing them while he fed. No wonder Kindred take the opportunity to be righteous when they're involved.
Strix. Paranoia Fuel and proud of it, and so repulsed by humanity in general that even draugr come off as being too much like the living for their tastes. They're the shadowy, unliving reminders that there are far worse things than vampires in the world, and they could be everywhere...
Some of the powers that vampires have are pretty nightmare fuelish in their own right.
The entire discipline of Obfuscate: vampires with it have illusion powers. They can be just about anyone they want to be. Or they could be right in the room with you this moment. Invisible. Watching you...
There's an entire discipline devoted specifically to Mind Rape by way of inducing fear, culminating in the abilities to scare people insane or even to death. Fittingly enough, it's called Nightmare.
If you're scared of mental illness, the Dementation discipline, allowing insane vampires the ability to induce insanity in others, is quite frightening.
Insomnium, a discipline which lets vampires get you in your dreams. They can even kill you in them by trapping you in a magically charged nightmare.
Hypnogogia, the discipline dedicated to messing with your memories. Erasing them, creating them, shuffling around details; they can do it all.
Nepenthe, which allows a vampire to mess with your body chemistry from afar, up to and including causing you to suffer a spontaneous lethal drug overdose...
The Gilded Cage: ritual magic that allows a vampire to control the city around you, turning every building and street into the vampire's ally and your enemy.
On a similar vein, the ultimate power of the Institutionalize discipline, Lord of the Manor, turns the vampire's building into a Genius Loci... one directly under the vampire's control, and intimately aware of every person inside. Needless to say, if the vampire doesn't like you...
The Show: this is why the Carnival bloodline is so repulsive; their bloodline discipline allows them to mutate and mutilate their bodies in various usefully grotesque ways, Body Horror of the worst kind.
The Taurbolium discipline is scary more for what it represents; an obsession with beauty so strong that it turns Blood Bathing into a ritual magic that succeeds all too well.
The Gustus discipline is another grotesquerie; its powers revolve around the Macellarius' obsession with cannibalism, including the powers to poison food with their blood so that prey becomes too drained to flee and vomiting acidic blood to subdue prey.
Phagia manages to be even more savage and disgusting than Gustus, for all its themes are similar.
Licencieux: you can't even trust your own senses, as vampires with this power can make you see, hear, feel, smell, even taste whatever they want.
Kingjan and Xinyao, which allows vampires to drain, manipulate and even literally destroy the emotions that people feel.
What's scarier than a vampire? How about a vampire who can excrete mustard gas at will, even turning into a unliving cloud of sapient nerve gas? Say hello to the Asphyx discipline, which does just that.
There are no fewer than threeNecromancer bloodlines; the Burakumin with their Getsumei, the Sangiovanni with their Cattiveria,, and the Apollinaire with their Carrefoure.
The Nburu discipline is like Obfuscate, but even better, when it comes to being in the wild. You can never escape a vampire with this discipline.
The concept of the Mérges discipline: a vampire is so full of The Power of Hate that he or she can literally transmute it into lethal poison.
The innocuous Mist Form power became this with the 2e update, all through one simple change. Vampires in Mist Form can feed in that form. And if the idea of a cloud of mist wrapping itself around you, impossible to fight back against as it drains your blood out through your open wounds, isn't scary enough? Mist Form Vampires can skip all that by just pouring down your throat and exsanguinating you from inside out.
Vampires can shrug off abuse that humans would die from, especially if they know Resilience, but they do so because they're not alive anymore. A vampire is literally nothing but a mass of blood and hate and hunger that is driving around in a vessel of dead meat and bone. Blow a hole the size of your fist in a vampire's head or chest, and it won't even flinch. Hack off an arm, it won't even flinch — and then it'll stick it right back on. You can run a vampire over with a car, shoot it full of holes, blow it up, stab it, and it just won't die. Think being a vampire hunter sounds fun?
By the way, did we mention that getting reminded of this little fact actually freaks out vampires, at least if they're doing well at holding onto their humanity?