What is the most horrifying monster in D&D?

What is the most horrifying monster in D&D?


The Oni. A weird ass looking shape shifter that uses that ability to infiltrate towns and families until it eventually has an opportunity to steal a child. It steals the child, transforms back into it's real form and eats the kid. Rinse and repeat.


Isn't that based off a thing from some mythology or something? Pretty sure witches did stuff like that.


It's based on a demon from Japanese mythology. I'm not positive what it's exact role in their mythology was but the Dnd Oni is at least partly derived from it.


Way back when they were "japanese ogres", then they became "ogre mages", (back around the time when AD&D had "Oriental Adventures", which in retrospect is pretty dodgy now) now they're "oni". Yes they are in part derived from the folkloric demon, but modern 5e has tried to take as much as it can without being too stereotypical. Glaive instead of katana, chain instead of samurai armor. Solidly nasty customers. I had one kill and replace an NPC bartender/Harper and had to question whether sending would still work, but I retconned my story so that he had always been the supposed agent.


To be fair, I recall Oni in classical depiction often carrying an Naginata-like weapon, or often a spiked club, making use of their build and strength


> I had one kill and replace an NPC bartender/Harper and had to question whether sending would still work, but I retconned my story so that he had always been the supposed agent. I would probably rule that sending works as long as the party had met the fake barkeep before the time of casting. If they’re thinking of “Bob the bartender” when they’re casting, they’re probably thinking of the last time they met.


That's about 95% of all the monsters in d&d. Tiamat and the tarrasque aren't even entirely unique to d&d


Half of all folklore seems to be "a way to frighten kids so they don't get into danger" (running away with strangers, wandering into the woods, playing next to swamps/rivers, etc.) Depressingly, the other half seems to be a way of coping with the high infant mortality rate. "It's so terrible that *the fairies stole your baby and left this sick/dying shapeshifter behind*. At least your baby is having fun with the fairies (and not sick/dying in this house)".


I saw a post either on here or on r/dndnext that totally made me rethink how I run Oni. It really drove home how absolutely terrifying they can be. Edit: found it! https://www.reddit.com/r/dndnext/comments/dmluvf/the_oni_is_awesome/?utm_source=share&utm_medium=ios_app&utm_name=iossmf


Not 5e official, but I'm a big fan of the false hydra, which is a similar-ish horrific threat. http://goblinpunch.blogspot.com/2014/09/false-hydra.html?m=1


Ilithids. I know they don't look like much, but the way they reproduce is disturbing to say the least. First they hatch some tadpoles and raise them to maturity. Nothing weird there, but what comes next isn't fun. See Ilithid tadpoles cannot be allowed to mature on their own, or you get one hell of a nasty creature once it fully develops, though it's just a rampaging beast and we have plenty of those. To actually get a Mind Flayer, they take one of their thralls, and allow a tadpole to enter into the thralls head through it's eye or other opening. Tadpoles are typically a quite bit larger than the human eye by the way. Once inside they begin feasting on their hosts brain while they're still alive, then it assumes control of the body, and finally mutates it into a proper fully grown Ilithid. It's not a pleasant thing to experience. If Ilithids capture you, being eaten or forced into slavery are actually the best outcomes.


I've known about the tadpoles in brain thing to make Ilithids but I've never heard about what a tadpoles turns into at full maturity without a host


It's called a Neothelid. It's a massive wormlike body with a gaping maw, tentacles that pull things into it's mouth, and incredible psionic power. It's mind is also underdeveloped in ways that make it difficult for psionic attacks to harm it. Illithids fear and despise them, working hard to ensure one can never come to be. If they're forced to abandon a colony and leave the tadpoles behind though, one will eventually devour all it's brethren and begin to grow and morph into something the Mind Flayers cannot control.


Thank you very much for this information


If you ever run an a campaign against an elder brain and your PCs don’t destroy the spawning pool you could have a neolithid come later in the campaign since they left all the larva as they would eventually feast on each other until one stood above all others and fully matured


I recommend this channel and vids: [Tadpole/reproduction info](https://youtu.be/WWJ73FELjiY) ["Secrets of mindflayers" info](https://youtu.be/_knGh2SOP4g) These 2 links specifically are about Illithids. Lots of lore. The channel dives into other stuff about DnD as well.


The thought of there being something of that nature that even they can't control is unnerving...


No kidding. Be sure to keep your guard up if find yourself in a seemingly abandoned Illithid colony. One of these things might be nearby.


We fought one in our homebrew campaign in the Anauroch desert, with the location we fought in being an old Netherese workshop with an Elderbrain skeleton in the middle. It was such a tense fight as we tried to burst it down before it recharged its AoE attack or devoured our Barbarian whole. As for lore, I love instances where monsters/enemies have something even they fear/hunt down. Just the idea that this thing is so dangerous that other Illithids kill it on sight is such a great visual, and really builds it up as a major threat, such as the first Flood level in Halo 1.


Don’t forget about the part where they time-traveled back to present day D&D from a future where they’re the undisputed masters of the multiverse… and have somehow ruined it so disastrously that running away is the best option.


>and have somehow ruined it so disastrously that running away is the best option. Not so smart now, are they!


I'm going to guess that they ate everyone


Same problem as vampires, when your food source is also your method of reproduction it creates tension, because by doing it even a little bit wrong you can put your entire way of life in jeopardy, because if you mess up one of them you can completely destroy two of the most important things necessary for survival.


We're getting closer and closer to Dark Ascension all over again


There's a movie called Daybreakers about this issue. Bats infected with the vampire virus turn the majority of the planet and remaining humans are farmed to near extinction


In Lords of Madness (where this theory is the most explored, a 3e book) it is an unnamed cataclysm/horror that even the Illithids couldn't figure out how to beat. Some sort of consequence of their all-of-reality-spanning, psionically-linked empire, that was making entire worlds "wink out" one by one. And this was in a lightless universe where the stars had all gone out and the Illithids ruled supreme over all. They literally had to invent a new psionic ritual that focused all their power on scattering the Illithids backwards through time to escape it (though I think the original plan was to send them all to a single period in ancient history, to rebuild their empire from the ground-up "even better this time", but they didn't have enough time to perfect it before they had to use it.) So...that's not terrifying at all.


I always imply that they fucked up and summoned something *bad,* in that classical but-the-dwarves-dug-too-deep way but with a trans-dimensional psionic twist. Where Dwarves and co typically stand and fight or at least *try* to unfuck it, the Illithids as obligate parasites just ran away like cowards.


Yes I agree completely. Illithids are singlehandedly the creepiest thing in the game, across all editions, for one simple reason IMO - they are the most alien by far. Even other Aberrations (despite the category containing many cool fucked up things, like Beholders, Aboleths, Slaad, the Morkoth) don’t come close. The mindflayer gets to be iconic because it eats brains, and that’s fucked up. Furthermore, I would argue that there is something especially alien and creepy about a creature that can levitate, fly, read thoughts, and psychically manipulate any creature or object it likes at will *without using magic* in a world where normally magic is either the or a major deciding factor in a fight. Because that says something about their nature, as beings. They’re so alien that they have no need of magic in a world where magic is basically functioning as a fundamental force that underpins all reality- including two dozen different fucked up planes beyond the material world - to a Mindflayer, even that is pedestrian and normal and beneath them, because all of those petty creatures (even the demon princes and arch angels) have to strain and apply effort to this force to *maybe* succeed at whatever they are attempting - whereas the Illithid doesn’t even have to try, they just do it as easily and naturally as you or I breathe. That’s fucking awe inspiring and terrifying in equal measure.


Illithids are super creepy and I do think they win the "creep race", but Beholders and Aboleths in particular come pretty close for me. I'd say the main reason the Illithids have them beat on creep-factor is _organization_ and their "secret backstory". You'll rarely find one by itself - they're either in an inquisition (three) or a full settlement (terrifying), while the other two tend to be more solitary (though Aboleth empires do exist and, even more rarely, beholder hives). Beholders are freaky af because a) _no one_ knows where they came from originally and b) their dreams literally reshape reality (which neither of the other two can do with such ease). Aboleth are freaky because they're almost like the polar opposite of Mind Flayers. Illithids are descended from a far-flung future race that sent themselves back in time to restart their empire (terrifying on its own!) Aboleth have _perfect ancestral memory_. They not only know there was a time before even the _gods_ existed, they _remember it_. And everything else since, with perfect clarity, as do any of their progeny. The sheer alien knowledge all three of these beings have is freaky as hell when you think about it. But Aboleth are the only ones that don't really have to expend any effort to _retain_ that knowledge, plus they're also immortal (when slain they just return to the Elemental Plane of Water). There's a reason even gods fear their meddling.


Aboleth come from the water plane. Hahahahahaha. My homebrew campaign has a city at the centre of a mercantile empire because back in the day it was plagued by disease and many foul creatures and a bunch of powerful Wizards & Warlocks made a pact with a (previously undefined) entity from the Elemental plane of water to wash the plague out of the city. But then they have huge waterfalls just getting in their way, and it’s already on an island so they build vast aqueducts hundreds of miles long going across the world, with this city at its heart. My players are actually already scheduled to go there soon because of unrelated plot reasons. Ah this in going to be so much fun to write up.


For a terrifying video of this, check out the Baldur's Gate 3 teaser video. [No. Oh God. Don't click this.](https://youtu.be/M8NA9Twr2ms)


Holy shit wtf why did i just watch that Also i kinda want to play balders gate now, its been on my "wishlist" for a while already


Patience. When it's actually done? Gonna be awesome.


That was quite good


Eberron has Brainstealer Dragons. They're *dragon Mind Flayers.*


Iirc there’s a statblock for them in Fizbans. Perfect timing because I’m currently running a homebrew campaign prominently featuring Dragons & Illithids.


*Ceremorphosis?!? It is to be AVOIDED.*


Why the eye? That’s not an opening. Why not an ear or mouth??


Not with that attitude it isn’t


As someone who has dealt with death in a very close proximity, I've always felt like the world at large is very desensitized to the concept of the Undead. Not the "cultured" ones like vampires or what have you, but whatever version of shambling corpse you like. The smell alone would render most people inert for a moment or two, no matter how much of a badass you are, the knee-jerk reaction to the smell of decomposition is profound. One doesn't really get used to it, at least, not the initial reaction. You will get used to the smell in the moment, eventually, becoming "noseblind" to it after some time. But the initial first wave can cause real (if psychosomatic) symptoms in people and I've met many who just straight up can't handle it. And that's just the smell of basic decomposition. Of, usually, just one body. Now add in, smell-wise, decaying blood, guts, festering wounds, missing limbs, on top of the fact that they gather in groups and are shambling towards you, trying to eat your face? That's pure fucking terror. Maybe not the worst terror in the world. But higher up the list than I think a lot of people would recognize.


My party ended up getting to a town that had Husks come out at night. Tell you what that was probably the scariest town I’ve ever come across in my time playing. We were all huddled up in the inn where the survivors took shelter. When it was my turn to take watch I decided to walk around town and “patrol” instead of just waiting and listening for shit like my other go players did. Who by the way heard other survivors just straight up getting murdered on their watch. I ended up getting spotted by one in the town courtyard and killed it using extraordinary measures but then like 10 or so showed up right after drawn to the noise. Needless to say I booked it quick but the thing about husks are is they’re fast. Insanely fast. I ended up having to cast gaseous form to get to a 2nd story building and stealth’d my way around until the end of my shift to make sure they wouldn’t chase me back to the inn. Fun night that was, absolutely terrifying I tell you. Nothing strikes more fear into your heart than feeling absolutely helpless to do anything and Husks sure put that kind of fear into you.


Agreed. A simple zombie fight would give virtually anybody PTSD if it was real. Adventuring career over.


And if it's someone you've already met that became said zombie? Fugeddaboutit.


Yeah I was already f'ed up seeing my ex I did not need her show up rotten and naked and to bite me and a tooth to stay in the wound. Meanwhile I'm all traumatized and my GF acts like it's *my fault*. Like I called Elisha and told her and her buddies to try to kill and eat me. Idk who that guy she was with was either. He wasn't as cool or alive as me seemed like


Intellect devourers. A brain sized brain...with dog legs...that consumes your mind. Then once it's full and your empty it can hop on in your skull and take your husk for a ride.


Not only that. It teleports inside your head displacing your brain that's already in there after winning one intelllect challenge against you. If you are able to somehow force it to get out of your head your team has one round to get your old brain back in. Nowhere in the rules does it say where your brain goes when it teleports in and takes over. Oh and this is just a CR 2 monster as of 5e. Insane.


Well now I'm gonna be up all night wondering where the brains go.


Illithid larders. They're always near intellect devourers.


So the Intellect devourer is just like an illithid hunting dog. They are trained to go out and teleport dinner back home. I don't care what the monster manual say. This is my truth now. Also, so many damn parties would try to adopt one.


... that's what they do. In the old school at least.


\*mindflayer sees brain on floor\* "Five second rule!"


The monster manual says it's magically devoured when the Devourer enters your skull.


Not quite, it specifically says your brain is magically devoured, not just displaced. And it does tell you how to get your brain back. . . Just have someone cast Wish. CR2, everybody.


Woof. Thanks. I was about to flip through my books because if there _was_ a way to get your brain back in (even with a 1 round timer), I figured I would've seen it. I was about to be all excited they weren't _quite_ that nasty for well-prepared PCs, but nope. Wish! CR 2! Maybe if Body Snatcher at least require multiple successes/turns to work, yeesh...


The brain is consumed by the devourer, only by a wish spell can the brain be regained


Yep. One of them killed my level 12 Paladin pretty much instantaneously. I hate Devourers with a vengeance.


I say old brain get ejected out the ears... Or they swap locations. A brain in a jar becomes very terrifying very quickly. Is it the big bad? Or your friend?


Only CR 2, you're joking right? You have got to be kidding me. THAT is CR2? That can't be fucking fair at all.




Oh god, you just reminded me of the prologue of Baldur's Gate 3. They spent WAY too much money and effort making that one scene *disturbingly detailed*.




Story: One of the scariest scenes in years of AD&D campaign included this fight on the beach. Cold, misty rain falling. We had two psionics in the party, one psi-warrior hiding in our boat from a mob of anti-psi zealots, the other a psionic druid who pretended she only cast divine spells. Mob leader, a fanatical cleric, is haranguing us and firing up his side. Our wizard tries to reason with him."Psionics aren't monsters! They are people with special gifts just like you." "I say thee NAY! They are demon spawn. Behold the error of your misguided mind," bellows the cleric into the rising gale. On cue, our druid's head splits down the middle and out climbs a bloodsoaked Intellect Devourer. (She had been mugged the previous night during her watch by another priest and this beast.) The wizard lost his lunch. We were swarmed by the frenzied mob, as the Intellect Devourer splashed out to the boat to feast on more tasty psionic brains, doing psi battle all the way there. A flaming oil flask drops from the low hanging clouds. As the smoke drifts up we hear the sound of hoofbeats. Galloping down the smoke, the enchanted cavalier charges into battle astride the zephyr steed. The rest of us survived, but it was a near thing.


This is so cinematic, my god. Props to your DM and to your retelling.


My current campaign is facing a full scale illithid invasion, but they are currently dealing with the preliminary intellect devourer wave. Its a world of paranoia and terror every time they meet anyone.


Anyone whose played in a game of mine, treats these like spiders. Run away, burn with fire.




I actually just used one of these when I ran a session for a party that our DM couldn’t go to. Dream sequence but still fun. I also gave it an ability that allowed it to see memories and create a vision of the victims “perfect life”


Polite reminder that this monster was made up by a Make-A-Wish kid.


Yeah I was gonna say oblex too. A good dm could do some crazy shit with it


Now I want to make a campaign where the main antagonist is an Oblex who’s achieved sentience beyond its basic instincts.


Yup, this one right here


Rocs. Idk about what kind of lovecraftian mind fuckery that freaks most people out. The idea of being on a flat plane then seeing the shadowy silhouette of an eagle in the sky, slowly growing to ungodly proportions... if frankly the most terrifying thing I can imagine.


But even in the MM it says they aren't really interested in anything normal PC sized. It hunts elephants and things larger than that. Unless you're encroaching on their nest or making a real nuisance of yourself you shouldn't have to worry about them at all.


Players might be safe but that wagon or ship they are in... That's just the hard shell to get at the tasty tasty meat inside once it's back at the best


True. Not saying they aren't a threat at all, but rather in a standard traveling party where you just have your buddies and maybe some horses your risk of a roc attack is not super high.


By that logic you shouldn't have to worry about intellect devourers, or any monster with a set territory. The whole thing about this game is those "unless" reasons are bound to be crossed. You kinda get to choose when they are crossed as a DM. For example, Rocs with hatchlings might be willing to grab a small bite for their babies if they didn't find anything worth the hunt while on patrol. Or if a roc is trained to protect s territory, such as by giants who use them for this purpose, it might attack all intruders. Basically your reasoning would make 70% of the monster manual less scary if people said"They won't bother you unless..." well welcome to adventuring we deal in those "unless" reasons. The imagery of I giant fuck you eagle is frankly deeply unsettling and primal on a level outworldy horrors can't reach, fear of the unknown is juicy. Being in the situation of a field mouse with a hawk overhead is just more visceral imo


And then being picked up to be dropped for 20d6 no save.


Such an underutilized monster


Gotta grapple it first. Then pin it and take it with you.


Roc gets +13 on grapple, so it's good chance you're screwed.


I did that once! Polymorphed into a giant crocodile and bit back. "Oh no, you are coming with me"


I want to see my dwarf druid use his animal handling to successfully RKO a Rok from 3000 feet, then take it's shape and fly off as a flex


That would be fun, but animal handling only works on the domesticated, and a roc isn't a beast (so shape is out too).


The roc is so close to a beast that I might allow it as a one off (similar to adapting a spell with an arcana check), except even with circle of the moon you can only turn into max CR 6 creatures. Roc is CR 11, that's orders of magnitude stronger. You'll need an epic ritual for that.


I mean sure, you could also do a metal masked fighter or monk specializing in grappling and judo, or just go cliché and put on the luchador outfit but don't let this man distract you from the fact that in 1998, The Undertaker threw Mankind off Hell In A Cell, and plummeted 16 ft through an announcer's table.


20?! For real?


1d6 per 10 feet falling, max 20d6. Also people fall 500 ft. per found in D&D, which is stunningly close to real physics and terminal velocity, which you reach I'm the first round of falling. It'd really be more like 526 or something, rounding just makes it easy. If we assumed Toril was slightly less massive than Earth though it would be perfectly accurate. But Toril is bigger than Earth so...


Just means that the core is less dense. That's also why there are so many caves. Toril has a smaller mantle but an extra energetic core that gives a massive magnetic field with unusual properties. Used that description for a star trek game where the locals had magic.


You ever seen carnivorous bird absolutely tear into some dead or dying animal? It's gut wrenching; imagine the city-wide gore fest that is a roc consuming its prey.


Oh gods... a roc going ham on a city... bleurgh!


Ok, so back in the 2e version of Ravenloft, there was this form of vampire that was just a cloud of mist. It hungered for blood and tended to hunt people in the dark. Just the thought of exploring a dark crypt or abandoned house, only to start losing blood rapidly from SEEMINGLY NOWHERE is a terrifying concept. The runner up would be that spider thing that looked like a human head. It would spin a super strong thread at neck level that would decapitate you if you walked into it. Then the head-spider would crawl into your neck hole, animate your body and impersonate a human. *shudder* Edit: Oh shit, I [found a picture of it](http://www.mojobob.com/roleplay/monstrousmanual/images/headhunt.gif)




What the fuck is the second one called? That is some dead space shit


First one is Vampiric Mist, it exists in 5e (Yawning Portal book). I've always loved [this](https://static.wikia.nocookie.net/forgottenrealms/images/a/a4/Vampiric_mist-5e.png/revision/latest?cb=20180628183052) art for it. Like the mist has "veins" drinking your blood through your pores or something, uuuugh.


Slimes. If you have ever been burned by chemicals or fire you know how painful it is. Now crank that up to 15 because it’s not burning it’s being devoured by billions of micro organisms across your entire body at the same time. It’s only acid damage because your being eaten. Slimes are one of if not the most terrifying creatures to ever be conceived in my opinion.


Well, even you and I digest food with acid, so... And yeah, that's freaking terrifying. And worse, some of them eat your *stuff*, too. So even if you survive the attempt at live digestion, the next critter to happen along is more likely to succeed at killing and eating you. Is it any wonder adventurers drink to the point of blackout?


It has been said that burning to death is one of the worst ways to die. Up there with drowning. So why not combine the 2 by accidentally walking into a gelatinous cube? Seriously. Slimes reputation as one of the weakest mobs in video games is incredibly undeserved. Just because it’s a trend doesn’t mean their not the worst thing to step in at night.


Gelatinous cubes are fucking terrifying if played correctly, as ambush predators. They block a passage with bad lighting (they have blindsight!) and wait for you to walk into them. Then they envelop you (your chance of escaping from this is very small) and ten seconds later you're dead.


I thought Players made their Characters get blackout drunk so they could skip the DM-mandated RP session at the tavern and get back to combat!


Dude, the ones where if you touch one and it starts taking over and you become a slime. That one's fucked.


The Oblex is that but reversed. It becomes YOU.


Oblex specifically


The sibrex is pretty horrific. It looks disgusting and even if you beat it, its hard to get out of a fight without being horribly mutated. And instead of dying, your worst fate is to become a mindless mutated monster.


Was surprised to find this one, but dead on, my dude.


Gibbering mouther / orb / abomination. I'm surprised no one has mentioned these yet. Formless blobs of flesh, puss, eyes, and hundreds of mouths all speaking nonsense so out of sync that it literally drives people who car hear it completely insane. Fun times.


And each of those mouths and eyes are all that remain of their victims.


More than that, it *incorporates* their body into itself and changes them. It doesn't actually kill. If a gibbering mouther gets you, spells that comune with the dead or scry for you will go to the mouther. And you can't be resurrected or cross over to become a petitioner unless someone kills the mouther. ... that and it moves slowly because its biting the floor and dragging itself with people's front teeth to move. I can't even explain why thats as disturbing as it is. Absolute body horror.


I have an audio file specifically for Gibbering Mouthers that's a bunch of voices screaming, laughing, speaking gibberish, etc., rising and falling in intensity. It's worked really well as a mood-setter. :P Now I just need the sound of teeth scraping on concrete to add in...


Oh yeah, I'm making one of those. I found several on YouTube that didn't quite do what I was going for. I think I'm going to take one or two of those, impose them over each other at different speeds, then take the [slowed down SpongeBob theme](https://youtu.be/6EFGs08YQ64), the cathedral choir noises from Duke Nukem 3D, and random sex moans from some LoversLab mod and make myself a proper abomination. If at least one of my players doesn't hear it and say, "Oh *fuck* ***that!***" I will consider myself to have failed.


lol, that Spongebob theme is a great start for sure.


There's a scene in a movie in which someone gets beat up and he gets put on a sidewalk edge with his mouth open and the attacker stomps on his head. That's why.


I want to run a monster that's a cross between a mouther and an allip. Where the blob of mouths are uttering terrible, maddening secrets


Don’t forget if it kills you, it eats you pretty much instantly. No res, no chance. Just eaten body and new mouth pops up.


I'm not allowed to use them any more. Turns out it _really_ freaks out one of my players. They were gagging and dry heaving and screaming in-between. Straight up triggered an extreme phobic reaction they didn't know they had.


Rot grubs


Okay, what are those?


Theyre tiny grubs with like 1 hp. If they attach themselves to a creature they start burrowing into the skin. The creature must either pull of the grubs in the first round or apply open flames to themselves, taking damage, to kill it. After a couple of rounds, the rot grub reaches the heart and kills the creature


My uncle liked to hide those in sacks of food we’d find around goblinoid lairs. My cousin lost his first thief by reaching in without looking.


Yay, new nightmares! 😱


Comes in swarms and explode out of infected corpses as well! They appear twice in the Saltmarsh campaign before the characters are level 3. Traumatised the hell out of my players


Basically, maggots that chew into your arteries and make a beeline for your heart. You have to burn then out of yourself with fire damage, and if they reduce you to 0HP before you can do that you did instantly.


Are those in 5e? I miss old school D&D


I’d probably say hags. Played right, a hag can be ungodly levels of horrific. Things like fiends are scary, horrifying forces of evil sure, but there’s just something about hags as a concept that slips it into the psychological horror zone, a certain quality that unnatural extraplanar fiends just don’t have IMO. Other than that, probably necromantic constructs or shadowfell creatures


Probably because most players have experienced an "old lady" in their lives. So the idea of the hag is more palpable. Probably because their true form is so close to being human, but not quite. There are mutated humans in the game that don't look as human as hags, who are not even human in origin.


Yep. Older ladies are supposed to someone you're most safe with. Grammas, Teachers, etc.


Hags are literally my favorite monster as a DM. Their magic is creepy. They are creepy. One of my major story arcs revolved around an incredibly powerful sea hag.


I ran a hag coven arc that was by far the most fun. A trek through a cursed swamp. 10/10


Gibbering mouther. What the fuck were they thinking when they made it.


Aboleths. First off, they look freaky. They're greenish-albino squids with weird eyes and mouths. Their anatomy is wack (especially when you learn that their brain starts in their skull and is so long that it reaches their tail). They also reproduce asexually, so an Aboleth that's left alone in a dungeon for a few decades can reproduce a bunch and create a bunch more of itself. Secondly, they're immortal. An Aboleth that dies just reforms in the Elemental Plane of Water. And unlike Demons, Devils, and Rakshasas that have similar types of immortality, an Aboleth that is killed on their home plane does not stay dead. They keep coming back, and there's nothing that you can do about it. The closest to "killing an aboleth" you can get is using the Imprisonment spell, because even though they're still alive, they're at least prevented from interacting with the world around them and can't escape. Third, they can mentally enslave you and prevent you from being able to breathe air anymore. They can turn anything into their slave, so long as they're not immune to the charmed condition. If a group of Aboleths got together and didn't care about the temporary inconvenience that is death to them, they could swarm a Kraken and spam Enslave on it and eventually *get control of a Kraken*. Imagine how destructive that could be! Fourth, their memories. Aboleths have perfect memories. Not only that, but they have a genetic memory that lets them perfectly remember everything that their parent knew, as well as everything their parent's parent knew, and so on back to the first aboleth(s) that came from the Far Realm. Every Aboleth has so much knowledge that it is beyond mortal comprehension. You literally cannot understand how much an Aboleth knows, because that would require you to have the same genetic memory that they have. This lets them be repositories for ancient secrets and lost knowledge that the world has forgotten. This brings us to the fifth point. Fifth, they are older than the gods. In a way, they were the worlds' equivalent of gods before the gods came and overthrew their empire. Mortals used to worship them as gods, and it's not hard to understand why. They come back whenever they're killed, can perfectly remember anything any of their ancestors knew, can mind-control practically anything that they want to mind-control, and they look like aliens (because they kind of are). They're extraplanar abominations with powers and knowledge that rival the gods. *The gods are younger than the oldest aboleths*. And they all remember this. They remember how their empire was overthrown by the coming of the gods. They remember precisely how they lost the last war, and how they're even more difficult to kill than the gods are. They know their strengths and their weaknesses, and are plotting to take revenge, to finally grow into the great empire that they once were. And they might actually be the ancestors of the Illithids. The Illithids came from the far-distant and dying future, but they didn't come from nowhere in that reality. They're descended from something else, and what better option is there than the other squid-like alien race with mind powers and a penchant for warping other races and dominating them under their control? (Aboleths did it to Chuul, Kuo-Toa, and Skum, while Illithids did it to Gith, Grimlocks, Duergar, and a few others.)


YES. Aboleths are the real masters of the world. They play the longest long game and nobody knows exactly what they're playing for but they're almost certainly going to win. In a way the mind control is almost unnecessary but goddamn it makes them creepy.


Surprised no one said it yet: Giant Spider, or any variant of them like phase spiders, sword spiders and so forth.


You can essentially run the movie Alien for a low-level party using a Phase Spider, pretty fun.


Low level very little magic psrty, a couple of shadows will do. Kill the low strength players in a couple hits. Then take down strength players making them weaker each successful hit. Resistant to non-magic weapons


Star Spawn, one of my favorites. Cultists made of worms with immense power Night walker, creatures Frome the negative plane bent on destroying all life Bodak, people who worshiped Orcus and now are bent on destroying it's former allies


Don't forget that the lesser Star Spawn emmisaries automatically turn into an even tougher version of themselves when they die. If that's not terrifying, I don't know what is.


I miss me a good Maw of Acamar from 4th ed. A mobile mouth for a sentient black hole.


After I pulled some shenanigans, DM brought one into my story arc in the campaign. I still am scared of worms and wisdom saves because of a single Larva Mage


I'm surprised nobody's said nuckelavee. Upper torso of a flayed human with long arms ending in massive claws on the lower torso of a flayed horse. Screams are said to be the stuff of nightmares. Is basically a fey and undead combo. And that's just the dnd version. True lore is more terrifying than that.


Oh, there's an official statbock for the Nuckelavee? What edition? I threw together some homebrew stuff a while back when I included one in my game, but it'd be interesting to see how they handled it.


The rust monster. Or possibly it's distant cousin from earlier editions, the disenchanter. Literally monsters that don't hurt you, but eat your treasure. Most players would much rather die than lose their gear.


So much this. Shit's getting real when you have to erase your equipment!


Seen entire parties run from the rust


My DM just gave me a rust monster baby to raise. I'm a wizard so I'm going to train it to defend me from fighters


Dangerous pet to have around. You think it's bad when a puppy chews on your shoes? Wait until that baby rust monster chews on your gear! "Bad Rusty! Spit it out!"


I'm a wizard, I have very that will interest him. I am just going to teach him that the paladin has all the food.


Rust monster under a permanent illusion to look like a downtrodden St. Bernard. :)


A spawn of Kyuss. People already described rot grubs, but a spawn of Kyuss essentially has those, can utilize trypophobia as well, and when someone dies to the worms, they become another spawn.


Kyuss himself is pretty awesome...


I feel like slimes are pretty horrifying, and gelatinous cubes are pretty scary. Imagine just walking down a hallway when suddenly you feel your body meet sudden resistance, and next thing you know you're gradually being melted away inside a monster you can barely see.


Our DM has done undead bruisers we're calling Hook-beasts. Undead ogres with hooked chains they fling at you. If they get you close enough, their intestines boil out and grab you, pulling you into the rotting torso. If you hit them with Radiant damage, d4 black puddings slosh out and attack.


PC Bards


I wasn't expecting there to be a correct answer in this post.


Had a boss fight where our bard rolls a nat 20, jumps up on his chair and belts out the whole song "Power of Love" then claims he was casting Otto's Irresistible Dance on the BBEG through song.


A caster rolling a nat 20 for a spell that requires the target to roll a save sounds like a wasted nat 20.


Boneclaws. 8 foot tall undead with extendable scythe claws that can gore you from 20 FEET AWAY. And with a speed of 40, you can’t easily outrun them either.


It also can never die until you find and kill whoever it's bound to


I have a very nasty adventure planned with one of these if I ever get a chance to run a genuine horror campaign


remember they attach to ANYONE who is evil regardless of age ;)


Boneclaw is ready!!


The ones Gygax feared the most were the ones named by Tolkien, followed by Moorcock. He dared not even speak their names again. But, seriously, I would be careful about using the Atropal unless I were very certain none of the players had had a pregnancy not end well.




That's a good point. Especially if you use some of the official Atropal art. Nasty.


Anybody else hate the bodak? Cuz I hate the bodak.


Probably some of the shadow fell monsters as they’re just people that got horrifyingly corrupted and transformed by their own emotions.


False hydras. *Shudder*


What's a false hydra?


It's a monster that essentially looks like a hydra in regards to structure, but with heads that look like they are made out of warped human faces. They possess huge amounts of malevolent psychic power, to the point where they can exert control over entire towns. If one kills, its victim is erased from the memory of everyone that has ever met them. [False Hydra](https://dicecove.com/false-hydra/)


Okay, we crossed into existential dread much quicker than I expected. I am impressed.


I ran one of these recently... Very fun to plunge your group into the depts of paranoid 'wtf-ery' and the terror at the reveal was delicious. Highly recommend.


At first, i thought you were playing into the joke. But since you actually seem to not have heard of one, here's a [glorious example](https://www.reddit.com/r/dndnext/comments/9szb2i/i_ran_a_false_hydra_this_week_it_was_amazing_if/).






I don't know if that counts as it's not a licensed monster released in dnd 5e. It's definitely one of the scariest encounter concepts though


Crippling self doubt?


... **are you sure about that?**


*Begins sweating profusely.*


CR 100


Elder Oblex. It’s a slime on steroids.


Sorrowsworn freak me the fuck out. The Lost in particular. Fighting something that wants to Embrace you to death because it’s unfathomably sad is genuine horror stuff.


Most aberrations. They are basically the unimaginable horrors from the beyond who’s entire thing is being super creepy and melting people’s minds. Look up stuff like uvuudaum. They’re pretty scary.


If we take homebrew into account I think the False hydra is the most horrifying monster. Imagine having a party member die to the monster and their existence, memries, and even their place in history.. Forgotten. That is horrifying to me.


Anhkeg. So we’re walked along, the ground shakes and the wizard is gone.


Looking through these comments just makes me realize I have used pretty much every single monster here as big foes for my groups… maybe I should toss them some less terrifying enemies


Those weird ghost things from Spelljammer.


The wizshades, I think they're called? Basically crazy undead wizards that pop out of portals?


No the ones that can't die until they enter a crystal sphere.


As someone starting a spelljammer type campaign thank you


If you want more information about spelljammers try watching these videos. [https://www.youtube.com/watch?v=-aQ8aMnoA-E](https://www.youtube.com/watch?v=-aQ8aMnoA-E) [https://www.youtube.com/watch?v=-iZHTXOPbJw](https://www.youtube.com/watch?v=-iZHTXOPbJw) https://www.youtube.com/watch?v=-aQ8aMnoA-E ​ I've never read any spelljammer sourcebooks so it might just be common knowlege.


Mind flayers


It's not published in 5e yet, I think, but the phaerim always freaked me out. Stick their hands through portals to attack you, from well outside of range of most weapons.


Rust monsters, anyone using metal weapons or wearing metal armor, magical or not, are in danger of losing said items if you tangle with one. We used to joke that facing one of these would make a melee class, especially fighters, openly weep.


[Lord Ao](https://forgottenrealms.fandom.com/wiki/Ao) or the [Luminous Being](https://forgottenrealms.fandom.com/wiki/Luminous_being). Neither of them would actually be a threat to the average person, or even interact with them at all, but the idea of something so powerful has such complete control over the realm that not even the combined might of every god, archfiend, archfey, and being from the Far Realm could even get close to touching it shows just how minuscule we are. And that there is something even more powerful than that, able to create and destroy multiverses on a whim is the height of cosmic horror.


Mimics. They can be almost anything and once you fought one you become paranoid that everything is now as mimic.


For me it's Hags. The fact something will just kill you in your dreams kinda freaks me out


To me: gelatinous cube, because of what it is. It's just a blob of stuff that's alive and you don't know how. There's no brain, no muscles, nothing - and you can SEE that. The only acceptable explanation for it being alive would be if someone cast Awaken or Animate Objects, but they didn't. Even in the realm of fantasy, it's freaking creepy that a giant blob of gelatin with no other body parts whatsoever can move, fight, feed, and even think and strategize depending on the DM.


After running some sessions, I’d say goblins. Man they can slaughter some low level parties. Especially if you are tactical with them. Having run for new players you can really do some damage with those suckers. Also wolves. Pact tactics is insane!


"it's just one goblin in the middle of the road, how dangerous can it be?" Famous last words.


The false hydra. Pale white skin, ghoulish humanoid features, several heads. It sings to make you forget it ever existed, or that any of it's victims ever existed. The innkeeper swears he never had a wife in the morning after you rented your room from her, he has a breakdown upon questioning him about it but can't remember why.


Redcaps, and not the DND Official ones- the Kobold Press ones. Bonus action force a PC into a DEX save or get knocked prone, then three attacks- a bite and two pike attacks. 95 hit points a pop. Nasty buggers that don't look like much but are terrible.


A single pack of wolves. If your party isn't working together and the DM plays the wolves as wolves are to be played, party wipe up through Level 7-8.