Cosmic Monster: the Apotropaiadon

Something like a reptilian crab.  Instead of claws, a pair of eyeless jaws lunge and snap at the end of its "arms".

Atop its back is a metallic membrane that curls and flexes, like a crown, or perhaps the sail of a dimetrodon.  The flesh of the shoulders blends evenly into the semi-translucent metal of the sail.

Light is reflected off the reflective sail and into a non-Euclidean direction, where its true face is.  This is how it sees.

When it wants to get a better look at its surroundings, it stretches and turns its sail, like a man holding a mirror around a corner.  As it moves, you can glimpse reflections of its real face.

It uses mirrors to copulate with itself*, and then lays its eggs in the same mirrors.  An egg embedded in a mirror appears as an optical distortion that sometimes pulses and crawls, like a lazy maggot.  Note that the egg doesn't bend the mirror or have any mass--it exists only as a bizarre lensing effect.

If the mirror is cracked, it will bleed.  If it is broken, it will disgorge the mangled larva and alert the parent.

This is the first cosmic monster that I've written about that is capable of easily communicating; you may want to brush up on your outsider psychology.

from MightyToy.com

They are often called here in order that they might be coerced into guardianship, hence the name.

Apotropaiadon

HD 5  AC chain  Bite 1d12
Move human  Int 6

Rewind -- Can undo the last 6 seconds (a combat round), at will.  Creatures who are engaged with the apotropaiadon will eventually notice this time-jump, while other creatures won't.

Option: Subtle Rewind -- The apotropaiadon begins combat (or negotiation) already knowing a good chunk about the party's abilities (or disposition), since it has already used this ability a few hundred times before the party noticed, learning by saying provacative things and making bold attacks.

Discussion

Yes, the apotropaiadon can easily stalemate forever.

Yes, the apotropaiadon can easily just reset the combat round until the PCs all have missed their attacks and the apotropaiadon has succeeded on it's attack rolls.

However, you can't just say "the apotropaiadon is going to keep rerolling the combat round until it gets the results that it wants, so let's assume that all of your attacks are critical misses and all of the apotropaiadon's are critical hits", since there is a chance that the apotropaiadon might die from a critical hit on one of the rounds.  If it gets stabbed in the heart, it dies instantaneously, and never has a chance to use its ability.

My party eventually killed it by trapping it in a room with a crush-trap ceiling for six seconds, and then activating the trap.  Since the apotropaiadon couldn't rewind to a time before it was trapped in the room, it couldn't escape through it's rewind ability.

After rewinding time several thousand times and attempting everything it could think of (attacking different parts of the door, trying to jam the mechanism in different ways, pressing every brick in case it was a secret "off" switch) the apotropaiadon gave up, and died cursing the party on the other side of the door.

At this point, the party was not far from giving up themselves, having pulled the same lever a few thousand times.  (At least in the fiction.  The players around the table were like "fuck this guy, my character is going to pull the lever a million times, and talk shit every time".)

Cosmic Monster: the Xantherium

The floor was spotless a minute ago, but now a yellow spatter blooms in the stone.  They look like yellow carnations, trampled in the mud.

They do not move--each stain is stationary--but the whole pattern moves, like paint spots dripping from an invisible brush, slowly spreading away from the closed door they seem to have crept under.

They pause for a second, after entering the room, thickening as they darken.  And then then the stains head straight for the two thieves.  They appear like footprints.

From all around them, they can hear the stone groaning in its sickness.

More yellow spots gather, like clouds on the horizon.  They creep up the walls and dapple themselves across the lintel.  The stains are reaching, like the arm of a leper.

Finally, one of the thieves can bear it no longer.  He throws his pack on the ground and sprints across the stain.  He will kick open the door and sprint out, where the sunlight will warm his pale face.

His first three steps cross the yellow stain without incident, but on the fourth, his foot passes through the floor as if it wasn't there.  There is the sound of snapping bone and then the thief is prone.  His leg missing beneath the knee.

There is a moment of cross-section, where the entire meat of the calf is visible, before it is obscured by the profusion of blood.

A second snap, and then his arm is vanished.  Another snap, and another.

Soon there is nothing left of the man except crimson pools.  There is a small sound, like many cats drinking milk at once, and then the blood is gone as well.

The stain has fattened itself, and now the spots are thicker, darker, and more complex.  There is no longer any clear stone between the individual stains, which cover the floor like the roiling of slow smoke.

The second thief watches the murky roses of the stain creep closer.  There is some larger pattern to it.  Here he can see where a certain thickening hints at a low-slung jaw.  On the far wall, there are implications of an enormous eye.

The thief backs into the final corner, an island of grey that is slowly sinking into a yellow sea.  Unless he thinks of something quickly, he will die.

Xantherium (Stain Form)

A xantherium is more like an infection that materials can catch.  Just like rhinovirus colonizes the wet epithelial lining of our throat, so does a xantherium move along the interface of two different materials of vastly different densities (most commonly air and stone).  This is an oversimplification, but it's a start.

It's large.  Maybe 500 square feet (~50 square meters), if it was all gathered in one place.  But it isn't all gathered in one place.  it's scattered around a denser core, like a flock of birds.

You can deal trivial damage to it by damaging the material that it moves through (e.g. chipping away at the stone floor) but it is likely to encircle you before you can deal more than a point of damage to it.

It moves at the pace of a tortoise.  It is attracted to the smell of meat, and a trail of blood can be used to lure it.

Attacks -- It gets 3 bites per turn, no two of which can be made within 5' of each other.  Each attack bites off about a foot of material and swallows it, dealing 3d6 damage.  Imagine a crocodile sticking its snout out of the floor and taking a very fast, very sharp bite.

Weakness -- It has a weakness.  You can pick your own, but I like sound.  Vibrations in the stone.  These drive it back, but they do not damage it.  Any sound lound enough to drive the Xantherium back is also loud enough to incur a roll on the wandering monster table.

Sound doesn't cause it pain.  It's closer to disgust, or religious revulsion.  (Simpler creatures are motivated by things such as pain and pleasure, but the Xantherium is a philosopher, and its prime motivators are philsophical in essence.  However, the mind of a Xantherium is so alien to us that this information is almost meaningless to a prospective interviewer.)

If it is ever cornered by the disgusting chimes, it will manifest itself (nearly) fully in our own dimension.  See below.

Xantherium (Beast Form)

Eight arms sprouting from a shared nexus, shaggy and bilious yellow.  Each terminates in a trio of spade-like claws, which it normally uses to pull itself sideways through space.  (It is a mole, deep down.  If you have a mole in your party it may be able to communicate.  No other creature has a chance.)

Four arms point up, and four staggered arms point down, but they are all the same arm.  (This is literal--any injury to one arm is mirrored on the others.)  It is about 10' tall.

You will only see this form if it is desperate.  Expect it to fight as a desperate animal would.

HD 6  AC none  Claw 2d6
Move dog  Int 6

The Staff of Quiet Bells

A metal quarterstaff, hollow and with an octagonal footprint.  When held against the floor and rung, it creates a muffled chiming that drives the Xantherium away without provoking any wandering monster checks.

If held in the middle and rung overhead, it makes such an ungodly clangor that you can basically pick how many wandering monster checks you want to invoke.  It can be heard up to 3 miles overland, on a dry day.

Discussion

Honestly, you could leave out the Beast Form and it would probably work better as a Lovecraftian horror.  (If you can kill it with a sword, it's not very Lovecraftian.)

I only included the beast form because that was how I originally conceived of it, and now it persists as a vestige.  I also like being able to make everything in the dungeon theoretically killable, because I'm a completionist at heart.

Is the weakness to sound a good idea?  Maybe.  It's better than fighting the stain with a sponge and soapy water.

You could do light.  Daylight is a little too scarce for a dungeon, though, and the party's only option would be to flee.  Torchlight has the opposite problem, and is a little too easy to provide.  (Sound at least, incurs the cost of a random encounter roll.)

If you were going for something truly Lovecraftian, the worst you could do is something like an emotion.  I mean, it might be fun to have the PCs make out and confess their feelings to each other in order to drive back the stain, but a cornerstone of Lovecraftian horror is that there is absolutely nothing of any value in a human's mind, body, or soul.

Water might be a good one.  (Holy water, perhaps.)  But then you run the risk of the party buying gallons of water in order to trivialize the Xantherium.  (This may be acceptable or possibly desirable, depending on the dungeon.)

This absolutely isn't something that you can just drop into a game.  It requires careful consideration of two factors.

1. What can drive the Xantherium back?

2. How will the players learn of this weakness?

HD 1 Cosmic Monsters

When most people think about cosmic monsters, they probably go to Cthulhu and other Lovecraftian horrors.  Big, incomprehensible things that cause insanity when you look at them.

This is a pretty limiting definition, which is too bad.  It makes it tougher to use those themes at low levels.

not cosmic in any way, I just like this pic

Anyway, here's my attempt at some otherworldly monsters, who clearly aren't from around here.  My design guidelines:

1. Weird Biology

Not just "it has tentacles and a bunch of gibbering mouths".  Those things are weird because they differ sharply from normal terrestrial biology.  They are highly unnatural (perhaps even impossible) without being hard to conceptualize.  Impossible biology is the goal.

2. Weird Mechanics

Let the mechanics fit the theme.  I don't want them to attack and defend the same way that regular monsters do.  Their mechanics should reflect how unnatural they are.  Ideally, the players would have a moment where they say "oh fuck, I just realized how this thing fights".

3. Threatening

I'll admit that this one is debatable.  I mean, you could write a good story about a warlock summoning some fucked-up abomination that merely drags itself around for a few pages before dying messily, poisoned by our atmosphere or something.  But I want monster.

A really good follow-up post to this one would be Non-threatening Cosmic Monsters.  Or at least, monsters that don't kill you.  Can you write a monster that would horrify the players without threatening them?  (Of course you can.  That's why this is such a good prompt.)

Dendricules

On the wall of the dungeon, what appears to be a tiny tree grows sideways.  It has no leaves, and its limbs are translucent as the thinnest skin.  If it were standing on the ground, it would be about 3' tall.

All at once, the tree flies apart, and the separate branches come twisting through the air like stiffened bubbles.  They hunt like a flock of fallen leaves, close to the floor.  Some are wobbling forks, while others are linear, and coil through the air like arthritic worms.

HD 1 (HP 1)  AC leather  Bite 1d6
Move as butterfly  Int 6  Mor -

Breed - When a dendricule hits you, it creates a new dendricule with HP equal to the damage dealt.  This ability works on any creature with a fleshy body.

If no other prey is available, dendricules will eat each other, eventually producing a mass of 1 HP dendricules.  Then they will reform the "tree", and wait.  They can wait a very long time.

Noctule

It looks like a flat piece of ash, the size of your hand.  Or perhaps a shred of black paper, something a magician could easily fold up and conceal between his fingers.

It flies through the trees like a hawk, and all at once it pivots along some invisible seam and heads towards the knights.

It corkscrews as it flies, spinning like a pennant in the wind.

HD 1  AC chain  Attach -
Move as hummingbird  Int 6  Mor -

Eyeball Attacker -- Regular armor is useless against a noctule.  Instead, it attempts to burrow through the eye sockets.  Fitted goggles give +2 Defense.  Eyes clenched shut = +4 Defense.  Eyes clenched shut with both hands covering sockets = +6 Defense.

Papery -- Any fire damage instantly kills it.  If it would take any piercing/slashing damage, it instead splits into two smaller noctules, each one with half of the HP (round down).  If this would result in a noctule with 0 HP, it instead dies.

Burrow -- After attaching to its target's face, it burrows in through the eye socket and consumes the brain through the optic nerve.  This occurs automatically on the next turn, and in invariably fatal.  The person's life can be saved if a torch is applied directly to the noctule (and the eye) during that turn.

Once a noctule has killed a target, they remain in the back of the eye socket for several hours, digesting the cognitive properties of their prey.  During this time, they are iridescent, and fragmented memories can be seen on their skin.  A careful hand can carefully remove a dormant noctule from the back of an eye socket and store them in a jar.

They reproduce asexually, by making nests in porous materials, often in a corner.  These nests resemble inky stains.

When killed, all that is left of a noctule is a small amount of foul liquid.

Earth Elementals and Gargoyles

On Centerra, everything is alive, to a greater or lesser extent.

Every mote of dust has something of a soul.  It would be a stretch to call it sentient, and yet even even that speck has something of experience, of a felt history.  (These micro-minds are what goblin filthomancers rely on.)

Humans have an easy time personifying fire, wind, and water.  Even a simpleton can often divine the intentions of these things.  The wind can be playful.  The sea can be angry.

The lives of stones are rarely given a thought, and yet they exist, just outside of the light of our cultural campfire.

Two things prevent humans from appreciating the stories of stones.

First, the life of a stone is very slow.  So slow that it is almost impossible for us to appreciate it.  A grain of sand will be born, incorporated into a sedimentary rock, and eroded an average of six times before it is truly dead.  This takes hundreds of millions of years.

Larger stones have even slower lives, and slower minds.  The Fighting Mountains have been locked in a deadly melee for almost a million years.  For them, this is a frantic struggle.  To us, it is scenery.  (This hasn't stopped the local monks from studying the mountains' actions, however, and learning kung fu from them.)

Far beneath Clavenhorn, at a place called the Second Omphalos, the Church operates a system of tubular "bells" that penetrate deep into the planet's crust, along with a separate system of parabolic caverns that grow a certain type of crystals, their growth visibly affected by telluric currents and the subsonic groans of the tectonics plates.  They are talking to the planet, at a rate of a single word every century.  Her name is Phosma.

Second, the life of a stone is inverted.

They are born huge, powerful, and wise.  Cut from the magma and shaped by the subtle designs of the planet herself, the mountains rule over their brethren.  (Every snow-capped peak is a crown, and that is why Centerrans never tread on the mountaintops.)

As they age, they dwindle, crumbling into feebler boulders and grains, each only a fragment of that molten wisdom which once fattened and instructed them.  Of all the secrets of the deep earth, the youngest stones know the most.

Compared to us, their senses are dulled.  They operate on a slower timescale, and their only sense that truly overlaps with our own is touch.  (Sound is approximated through long periods of resonance.)  Truly, you could dance atop a boulder for a month before it noticed you.

by Yefig Kligerman, for God of War

Earth Elementals

I bet you're only interested in how to fight one.  You brute.

I've already written about how you would fight wind.  You must trap it, smother it, chain it.  Immobilization and death are synonyms.

And fire elementals are destroyed as directly as you might think--you must deprive them of their fuel, or of their oxygen.  Little else can damage the inferno.  And yet this is complicated by the tremendous energy of a fire--it's capacity to throw embers, suck wind, break windows, and escape into the forest where it can become unstoppable.

Earth elementals are an aberration among their brothers.  Usually born from some great insult or fear, many are created specifically to fight mankind, which is now slowly becoming recognized as an existential threat.

Compared to other earthen creatures, they are blindingly fast, and absolutely suicidal in much damage they do to their own bodies in the process.  They are similar to a human who could run 100 miles an hour, even as their tendons snap and their skin peels off from the cruel velocities, which their substance was never meant to take.

Earth elementals are most often made form quartz.  It has the extreme durability that their berserk metabolisms require.  Other elementals are made from similarly durable rocks: moissanite, chrysoberyl.  They throw themselves into their tasks with suicidal intensity, grinding themselves into dust in the space of only a few hundred years--a heartbeat among the mineral spirits.

Compared to humans, an earth elemental moves at a crawl.  A man with two broken legs could pull himself faster than an earth elemental's sprint.

A small earth elemental (the kind that you will encounter in a dungeon) is going to be 3 m tall and weigh 10 tons.  They will have the "lower body" of a tank, or perhaps something like a many-legged tortoise.  It's "upper body" will be something of the body plan of a crab, with broad arms ending in crushing claws.

The arms move a good bit faster than the legs, but still extremely slow by our standards.  An earth elemental trying to crush a human is comparable to a human trying to catch a flying mosquito with their bare hands.

You are safe from them as long as you stay out of melee range.  You will not be able to chisel them to death unless you get inside melee range.  A fight with an earth elemental will likely be a running battle, crossing many rooms of the dungeon as you find ways to wear down the implacable stone.

Earth elementals are intelligent and capable of speech, but you must talk to them very slowly.  About one word ever 10 minutes.

Lvl 8  AC -  Grab x2
Mov snail  Str 24  Int 10  Mor 10

Any attack against an earth elemental is going to hit it.

Explosives deal full damage.  Pickaxes deal 1d6 damage.  Bludgeoning weapons deal half damage.  Pretty much everything else (including lightning and acid) deals 0 damage.

Each turn, it tries to grab two adjacent enemies and crush them to death.  The earth elemental attacks with a -10 penalty to its attack.  On a hit, a target is grabbed.  If the target is still grabbed at the beginning of the earth elemental's next turn, the earth elemental automatically deals 4d6 damage to them.  It can then drop them as a free action or throw them for another 4d6 damage.

They can move through one dungeon room every 10 minutes.

some Notre Dame gargoyles by Eugene Emmanuel Viollet-le-Duc

Gargoyles

Like humans, stones are also susceptible to demonic possession.

Gargoyles do not appear to be made from stone.  They are cold-eyed beasts that spend a millennia carving a body for themselves, and another millennia digging themselves free from whatever vein spawned them.  No two appear exactly the same, and yet they tend to favor the same features, sculpted accord to terrify the primeval mammal at the heart of man.

Powerful shoulders, low-slung jaws, talons as thick as a shovel, and spiked tails are common.  Many of them wear wings to honor their Satan, although none of them can fly.

After the Church successfully invaded Hell in 788 TFM and overthrew Satan, many demons were forced to take the Oaths, becoming devils.  Gargoyles were included in that number, and to this day a great many of them have been installed on cathedrals, in order to serve as guardians in the cathedral should ever be attacked.  (They are usually awoken by ringing a certain bell, within the church.)

Many gargoyles chose their bodies before they had a chose their purpose.  Many are insecure about their lumpy, plodding bodies that would built to terrify uncivilized, brute humanity.  Many are ashamed to sit beside the carved angels of a cathedral's walls, and can only be glimpsed lurking in the recesses.

HD 4  AC plate  Atk 1d12
Move human  Climb ape  Int 8  Mor 12

Autopetrification -- In place of a move action, a gargoyle can turn from flesh to stone, or vice versa.  Their senses are dulled while in stone form.  If killed, a gargoyle instantly turns into stone, trapping any piercing weapon that was used to deliver the killing blow.

d100 Mutations

After a great deal of research, discussion, and computer-aided simulations, I have discovered that the best mutation is a lobster-claw arm.

I then turned my attention to writing the best possible mutation table, which I've posted

>HERE<

and now I'm going to talk about the design process because that's what you do with a blog.

So, Mutations. . .

Mutations are very OSR, because they're (1) random, (2) impactful, and (3) modular.

(1) Yes, you could make a mutation table that was small and/or linear.  Like a mutation track for turning into a fish man.  But they're usually random, with dozens, hundreds, or thousands of entries.  Mutations are essentially chaotic, a fact supported by both biology and Warhammer.  The less predictable mutations are, the more genuine it feels.

(2) And while mutations are often cosmetic (new skin color), others are very impactful, conferring new abilities or slaying characters directly.

Most games "play to find out"--we roll dice during combat to for the sake of emergence--but games vary in how impactful they are.  Some games limit you to the boundaries of the arena, while others are happy to let you kill your characters, turn important NPCs into bee swarms, and/or sink a continent.

Those two traits (random, impactful) are also shared by the the Deck of Many Things.  People who hate the Deck of Many Things also tend to hate random mutations, because both can derail an expected adventure so quickly.

(3) And mutation tables tend to be modular.  They aren't bolted onto any other subsystems, and don't usually depend on a particular setting.

People have written some good ones: slack ratchet, Scrap Princess, Skerples

How Big Should a Mutation Table Be?

A small mutation table (< 100 entries) will tend to have more good entries, and less chaff.

A large mutation table (> 100 entries) will tend to feel more random, and have enough variety to please Nurgle.

That's basically my justification for writing a d100 table.  I'd love to write a d1000 table, just for the bragging rights, but around 150 entries I started found myself writing down some mediocre entries.  There's a sweet spot, I think.

How Lethal (and Beneficial) Should a Mutation Table Be?

That's a great question.  I originally had it right in the middle: 30% good, 40% neutral/cosmetic, and 30% bad.

I went on to split the bad into 20% bad, 10% lethal, because I really like the idea of someone losing their ability to breath air in the middle of combat, or burning a hole through the floor as they die painfully.

Mutations should be rewarding enough for players to be tempted, and dangerous enough for them to be reluctant.

So if the worst possible result is basically just death, how good should be best result be?  Originally I had a couple entries that were basically just superpowers.  Those have been toned down or removed.