OSR: Myconids, Part 2

Part 1

Cave fungi are much less common than video games and RPGs would have you believe. They do exist - fungi exist everywhere - but they rarely form little mushroom colonies. Caves can be used to farm fungi, but they rarely occur naturally in any noticeable profusion.

Thankfully, this is fiction.

Even fictional fungi still need a food source. In my game, the great fungal "valley", a deep and damp cave system full of steam, water, and fungi, is fueled by coal. Greats seams of it. An anthracite palace 300' thick. Water carries detritus and nutrients from the surface and from other parts of the Veins. Everything seems to drain into the Fungid Valley.

There is no mushroom forest. Mushrooms are ephemeral tools, lasting just long enough to spread their spores. You can't build a house in a mushroom; it would be like building a house from candyfloss and bread dough. But the caves are full of fungi.

Shahab Alizadeh

A Kingdom of Rot

Every section of the Fungid Valley (or every hex, if you're using a map), has a ruling fungus. It crowds out all the others, feasting on coal, bickering with its neighbors, seeking advantage and expansion in a silent alien war. Borders change slowly. Mortals hardly concern a creature weighing fifty thousand tonnes and mostly buried in water-soaked coal.

The King Fungi are merely the largest inhabitants of the Valley. They are the coral substrate. In the tunnels the create, in the vast web of waterlogged passages and chasms, an entire coral reef proliferates. Small patches of fungi grow on outcrops of rock or fragments of fallen coal. Some grow on dead myconids, dead insects, corpses of foolhardy explorers or desperate refugees, or wooden debris from the surface.

The Valley is alive in a way that most caves are not. The stillness and solitude of the Veins is replaced with buzzing, churning life. The air is filled with spores and insects. Every surface crawls with fungal life. Mushrooms erupt and vanish. Strange creatures, adapted to the bizarre environment, flourish. Eerie light from glowing fungi or microbial rot. Clouds of spores, delicate flies, or coal dust. Water and slime on every surface. 

1d10 Mycelium Colour Smell Mushroom Colour
1 Grey, with white knots Musty, like old books Red, bright, almost metallic
2 White, with faint hairs Freshly cut hay Yellow, pale, mottled
3 Grey, almost translucent Mashed rotting grass White, bulbous
4 White, with milky secretions Carrots White, faint pink stripes
5 Brown, fading to yellow Nothing Red, marbled like meat
6 Clear, like glass Blood Blue, dark, almost purple
7 Yellow, sharp and angular Menthol cold Orange, pale, black spots
8 Black, pulses slightly. Pepper Yellow, vibrant, striped
9 Grey, with transparent bits Dust Purple, iridescent, sharp
10 White, like bone Acrid smoke and ozone Grey, greasy, white spots
Maxim Verehin

Creatures of the Fungid Valley

A coral reef ecosystem. Glorious, convoluted, and full of life. All those odd, disconnected bits of the D&D manual make sense when seen together.

1. Mushmice

HD: 0 (1 HP)
Appearance: a mushroom cap with tendril legs. Moves like a mouse.
Wants: to find food (see below) and sporulate
Armor: none
Move: normal
Morale: 6
Damage: spore attack (see Veins of the Earth pg. 59)

Mushmice scuttle from cave to cave, searching for their favoured food source (corpses, coal, rotting wood, etc.) Once they spot it they scuttle forwards, sporulate, and then try to lure predators away from their seeded fungus. They are delicious. There are thousands of nearly identical varieties. Any given mushmouse has a 1-in-6 chance of being poisonous. They live for 1d10 days.

2. Glowing Fungi

HD: 0 (1 HP)
Appearance: a glowing branch of fungal growth, fan-like and sticky.
Wants: to attract insects
Armour: as leather
Move: immobile
Morale: 4 (can retreat into a pocket)
Damage: none

Glowing fungi, semi-permanent mushrooms inflated with water, light the Fungid Valley. Insects, attracted to the light, become trapped in the sticky hairs covering the fungus. It digests them and grows. If threatened, it deflates and retreats into a pocket in the rock. Cut one off in time and the luminescence lasts 3 hours, or more if fed with insects.

3. Burrowgrub Swarm

HD: 6
Appearance: a buzzing cloud of thumb-sized winged grubs
Wants: to eat fungi, lay eggs
Armour: none
Move: 2x normal
Morale: 8
Damage: 1d6 per round to everyone in the swarm's area (20' cube). Any attack that deals 3 or more damage implants an egg.

A roving terror in the Fungid Valley, a swarm of burrowgrubs is a constant threat to Myconids (and anyone bearing fungal infections). The swarm attacks, implants eggs in the fleshy head-caps of Myconids (or the flesh of anyone it thinks might be a Myconid), then departs. The eggs hatch in 1d6 days, leaving an unsightly scar and draining 1 permanent point of Constitution. They can be removed with a knife.

4. Sporebat

HD: 1
Appearance: a large grey-black flying fox with luminescent green eyes
Wants: to move to new areas and sporulate
Armour: none
Move: normal, fly normal
Morale: 8
Damage: 1d6 biting. Spore attack (see Veins of the Earth pg. 59)

Sporebats are another method for distributing spores. They hop and climb and glide through the Fungus Valley, seeking exposed coal or rotting wood. They are mostly harmless, and will climb all over myconids and other moving creatures. They will happily nest on traveling PCs. Each one fills an Inventory Slot. They can be trained, but will usually flee at the first sign of danger. If you see Sporebats fleeing, flee alongside them. Any given sporebat has a 1-in-6 chance of being poisonous. They live for 1d10 days.

5. Fungifish

HD: 2
Appearance: large blind trout
Wants: to move to new areas and sporulate, to drag food into the water
Armour: as chain
Move: swim normal
Morale: 10
Damage: 1d6 biting, Save or be knocked prone.

Fungifish are fat white mushrooms spawned by a semi-aquatic fungus. They can swim to new areas before sporulating and even crawl on land for a few hours. They want to drag creatures into the water and drown them to create more food. They will ignore Myconids and other fungal creatures, but anything else is fair game. They live for 1d10 days, or 1d10 hours out of water.

6. Gill Beetle

Stats as a giant beetle, AD&D MM p. 9

Gill beetles have adapted to life in the Fungid Valley. Their pin-point tread doesn't disturb the fungus floor. Their mouthparts have evolved into net-like gills to scoop spores out of the air. Their carapace is often covered in small fungal growths. Giants and grazers, they are rarely aggressive unless protecting eggs or defending territory. Hatchlings are the size of toy cars. The largest beetles could be used as houses. On the move, they block entire passages.

7. Adapted Humanoids

HD: 2
Appearance: stooped, worried humanoids in rags, covered in multicoloured fungal patches
Wants: food, safety, weapons, news
Armour: as leather
Move: normal, not impeded by fungal growths
Morale: 8
Damage: 1d6 spears or dagger. May also have Fungal Benefits (see below).

People can live in the Fungid Valley, but it is a hard, short, and dangerous life. Food is abundant; poisons are everywhere. Fungi colonize your lungs and mucus membranes. Adapted Humanoids move through the shifting and shimmering caves with ease, looking for food, hunting threats, and trying to stay alive. They make their homes from gill beetle carapace, bone, and rock. Few speak any recognizable language, but the fungi that infest their bodies often grant them supernatural abilities. Some, shockingly, might be people the PCs have met before, now seeking safety in the Fungid Valley.

8. Myconid (pre-sporulation)

Veins of the Earth p. 59
Active, questing, sprinting. Vicious and willing to kill. It's on a mission to find a spot of bare coal and sporulate. Lead it, guard it, steer it, or scrape a patch of fungus free and it will sporulate (as 2x random spore attacks, VotE p. 59, effects combined strangely). After sporation it will become slower and more docile. Any given Myconid has a 1-in-6 chance of being poisonous. On average, they live for 2d10 days, but some varieties may live for 2d10 weeks.

9. Myconid (post-sporulation)

Veins of the Earth p. 59
Guarding, waiting, thinking. Sometimes scraping at the ground to clear undesirable growths or attacking Myconids from adjacent zones. If they don't have weapons they will use their fists, bludgeoning chunks of mushroom flesh until nothing remains. Any given Myconid has a 1-in-6 chance of being poisonous. On average, they live for 2d10 days, but some varieties may live for 2d10 weeks.


 10. Psychomycosis Megaspores
Veins of the Earth p. 100
Tumbling along, looking for something with a nervous system. Sometimes difficult to spot them in the busy and spore-filled air.

11. Russet Mold

Expedition to the Barrier Peaks p. 29
Found in small patches in humid caves. Fills entire passages with a brown haze of spores if disturbed. Thankfully, it spreads over a very limited area in the Fungal Valley. Other fungi can typically out-compete it.

12. Vegepygmy
Expedition to the Barrier Peaks p. 29 
Russet mold does not produce Myconids or other mobile mushrooms to spread its spores. Instead, it colonizes other living organisms, creating the diminutive and dim vegepygmies. The spores of russet mold take over a living creature, pilot it to water, then try to kill it in a convenient area to grow more russet mold. Vegepygmies live for 1d10 months, or more if the creature they spawned from was particularly large and nutrient rich.

13 Black Pudding

 AD&D MM p. 10
Squelches slowly, digesting everything in its path and leaving a trail of bare coal behind it. The coal is rapidly covered in spores and fresh growth.

14. Gas Spore

AD&D MM p. 42
Can resemble any creature, from a Sporebat to a Psychomycosis Megaspore to a

15. Violet Fungi

AD&D MM p. 42
A classic flesh-devouring fungus. A purple blotch with thin wispy tendrils.

16. Green Slime

AD&D MM p. 49
Found in small patches with a ring of bare coal around it.

17. Brown Mold

AD&D MM p. 71
Usually found at the bottom of pits and drops, where warm creatures are likely to fall.

18. Yellow Mold

AD&D MM p. 71
Most colonies in the Fungid Valley are intelligent. Those that have eaten the brains of wizards can even be negotiated with, and may speak in strange burbling voices. They are not to be trusted.

19. Ochre Jelly

AD&D MM p. 75
The ochre jellies of the Fungid Valley are small and feeble. Travelers might accidentally pick one up or allow one into their packs, where it will feast on rations and flesh and grow surprisingly quickly.

20. Shriekers

AD&D MM p. 87
Shriekers collaborate with larger fungal colonies. They alert roving Myconids to potential threats or food. 1d6 (exploding on a 6) Myconids will arrive to investigate.

Shahab Alizadeh

1d20 Encounter Page Reference
1 1d6 Mushmice, scuttling
2 2 Glowing Fungi branches
3 Buzzing, then 1 Burrowgrub Swarm
4 2d6 Sporebats, flapping moistly
5 2d6 Fungifish in a pool or stream
6 1 Gill Beetle, roving AD&D MM p. 9
7 1d6 Adapted  Humanoids, gathering
8 1 Myconid, pre-sporulation, roving VotE p.59
9 1d6 Myconids guarding a fungal growth VotE p.59
10 2d6 Psychomycosis Megaspores VotE p.100
11 1 patch of Russet Mold EttBP p. 29
12 3d10 Vegepygmies EttBP p. 29
13 1 Black Pudding, squelching slowly AD&D MM p. 10
14 1d6 Gas Spores, drifting AD&D MM p. 42
15 1 patch of Violet Fungus AD&D MM p. 42
16 1 patch of Green Slime AD&D MM p. 49
17 1 patch of Brown Mold AD&D MM p. 71
18 1 patch of Yellow Mold AD&D MM p. 71
19 2d6 minuscule Ochre Jellies, crawling AD&D MM p. 75
20 1d6 Shriekers, hidden in other growth AD&D MM p. 87

Shahab Alizadeh

There's a Fungus Amongus

Myconids are a bit like Blade Runner replicants or Frankenstein's monster. They are created for a fixed purpose with a finite lifespan. They know virtually nothing when they are first born, but their minds are primed to absorb and catalogue information. They pick up languages rapidly. They can watch someone use a tool and then do the same task just as well, or learn to play simple games after a few attempts.

The can be taught self-awareness. They can be taught mortality.

In the Veins, philosophers are valuable as weapons of war. A philosopher who can speak to the Myconid slaves of an enemy faction, or immunize the slaves of their own faction against outside propaganda, is highly prized. Myconids can be taught to teach other Myconids; a chain of self-propagating ideologies and drives. They are neither naturally wicked nor naturally good. 

But, more dangerous than self-awareness, more dangerous event than the knowledge of death, is the knowledge of reason. A Myconid who is taught to reason can create new philosophies and tactics. They might question why they must live for so short a span.

Myconids cannot eat. They are born starving. Some Veins cultures have experimented with injections of mashed vegetable matter, rotting pulp, and blood; nothing supports a Myconid. They lack the ability to store energy and can only deplete existing stores. Some Myconids, restless and fearless, grow agitated at their pitiable lifespan and seek ways to avoid death. Lacking souls, they cannot cast spells or seek the usual paths to immortality.

Cunning myconids surgically attack their clone-siblings and graft new tissues to replace drained energy reserves. This method is risky and will not sustain a Myconid forever, but it can buy valuable time.


Even the smallest soul will do. A fly's soul is a meager thing indeed, but there are dark wizards in the Veins who manipulate souls with great ease. Giving a Myconid a soul is a simple matter for a necromancer. Newly empowered, a Myconid might seek spells and ascend into Lichdom, or, preferring the more certain path, drain life and vigour from others as a dread Fungal Vampire.


A difficult process. A host must be found and modified. Fungal tissues are stitched into every vein and nerve. Secondary fungi, to bridge the gulf between mammal and mushroom, are introduced. Strange elixirs and horrible potions fuse the creatures into one coherent whole. The process rarely works. Rarer still does the Myconid remain sane.

Emily Eliza Ellis

Fungal Infections

Spend any time in the Fungid Valley and fungi will colonize you. Some merely cause rashes and itching. Some can be deadly.

Every 24hrs spent in the Fungid Valley, Save or gain a Fungal Infection. The effects last until you leave the Fungid Valley and wash thoroughly with hot water and salt. Once you accumulate 3 different Fungal Infections you no longer need to roll.

2d6 Fungal Infection Mechanical Effect
2 Yellow spiky fungus in eyes and tear ducts. Blind, -4 HP
3 Grey-black fungus in lungs. Choking. -2 HP and Constitution
4 White slimy fungus in lungs. Phlemy. -2 Constitution
5 Grey fungus in armpits and groin. Itchy. -2 Dexterity
6 Black spotted fungus on arms and legs. None
7 White flaky fungus on feet and ankles. None
8 White puffy fungus on eyelids and tear ducts. None
9 Soft white fungus in mouth and noise.  None
10 Red fungus in joints. Painful spasms. -2 Dexterity
11 Purple fungus in nose and sinus cavity. -2 Intelligence and Wisdom
12 Orange-yellow fungus in ears.  Deaf, -4 HP

Suguru Tanaka

Fungal Benefits

You need to actively seek these benefits. Use your body as a test bed. Court corruption.
If you're using the GLOG, or any other system that gives class benefits as you level, you choose to roll on the Fungal Benefits table instead of gaining the normal benefit from leveling. You must have 3 Fungal Infections (see above). At the GM's discretion, certain actions (like eating specific mushrooms or deliberately cultivating certain infections) can let you select a result from the table rather than rolling. You gain +2 HP for each Fungal Benefit you gain. You may be unwelcome in some communities.

Fungal Benefits Table

1. Filter Lungs

Your lips are purple and your breath is deep, ragged wheeze. You are immune to the effects of dust, smoke, airborne spores, and poison gas. You can also hold your breath underwater for 5 minutes.

2. Spore Spray

Your skin is covered in tiny blotches. You sometimes sprout mushrooms. You can spray one random spore effect (Veins of the Earth p. 59) by taking 3 damage. You can gain this ability more than once.

3. Myconid Spawn
You gain a hump on your back and all your hair falls out. You can take 1d6 damage and consume a ration to create a miniature Myconid helper. It is 2' high and as strong as a child. The newly spawned Myconid has HP equal to the damage you took. It will live for 1d10+ [the number of Fungal Benefits you have] hours. You can have any number of Myconid spawn active at the same time.

4. Compost Guts

You bloat and your limbs shrink slightly. You can eat anything made of carbon as a ration: coal, rotting wood, corpses, scrolls, leather. It all counts. You are immune to ingested poisons, but alcohol deals 1d6 damage to you. You are coveted by Myconids seeking immortality.

5. Aersolize

Your flesh becomes pale and spongy. You can take 1d6 damage to fill a 10' cube with your flesh and spores. If anything passes through the cube for the next 1 hour, you are alerted to it and gain a vague idea of its shape and speed.

6. Fungus Sense

Your blood is latex and your veins are nearly solid. Plunge your hands into a mycelium to sense tremors up to 100' in all directions. You can tell how many things are moving through the area and how the fungus feels about them. You can also touch a Myconid or other fungal creature to learn how long it has left to live.

7. Spore Explosion 

Your eyes are constantly bloodshot. Your nails fall out. If you die, you explode into a shower of choking white spores. Everyone in a [level]x10' radius must Save or take 1d6 temporary Constitution damage every round they remain in the area. After 1d6 days, up to 30xd10 hostile vegepygmies with your face will emerge from suitable corpses in the area (assuming they are available). They don't have any of your memories but they might possess some of your quirks or mutations.

8. Spoilation

Your hands drip fuzzy white rot and your bones feel soft. You can choose to spoil and discolour any food, wood, or leather you touch. It rots, gains mould, and warps. If you infect grain or bread this way, anyone eating it must Save vs Fungal Hallucinations (see Part 3).

9. Fungal Regrowth

Your skin flickers with rapidly growing colonies. Any wound or cut reveals writhing white tentacles that stitch you back together. If you are not Starving or Dying, you naturally heal 1 HP per hour. You can consume 3 Rations and Save to regrow a lost limb. On a failed Save the rations are still consumed. 

10. Altered Mind
You constantly emit a cloud of fine grey spores. Your eyes are black and you weep black tears. You can speak with fungi and Myconids. They don't have to answer or obey you, but they will listen. Small fungi aren't very intelligent. Giant fungal networks have completely alien minds. Myconids and mid-sized fungi are your best bet. 

Part 3 will contain some rare and dangerous fungi, a hallucinogenic effects table, and treasures of the Fungid Valley.


  1. Your world building posts are freaking cool. Every time you write something new I want to include it somehow into my game!

  2. You mention fungi/creatures feeding on coal several times. I'm curious, is that something from real life? I mean I know coal is organic matter super-compressed over millions of years but it's become rock, right?

    1. There are, amazingly, coal-eating fungi. Not on the scale I've described, of course, but they do exist. Coal is a difficult material to digest but both fungi and bacteria can do it. It's not rock though. It's just compressed carbon.

    2. That's pretty incredible! And thanks for the blog link it looks full of brain tickling stuff.

  3. Talking about philosophy-as-fungal-mean-of-war: https://en.wikipedia.org/wiki/Rhizome_%28philosophy%29?wprov=sfla1

  4. Provided a steady supply of insects, it seems to me that the luminescent fungus might be a great light source if torches are rare in the Veins.

  5. You've got me thinking about what would cause a mushroom forest to actually persist.
    Perhaps it oxidizes into a solid, or it could be colonized by a fungus/bacteria that converts the material into something more solid.
    As for why, permanent mushrooms could shelter growing mycelleum, it could be territory denial to other creatures, or if each new mushroom grows from the top of the last one spores may distribute further. Of course it doesn't have to be for the mushroom's benefit either. The mushrooms may be preserved as housing or building material by forces with no regard to the fungus' health.

    1. As usual, Arnold got there first: http://goblinpunch.blogspot.com/2014/10/new-biome-great-rot.html
      You need a persistent fuel source. A forest (living) works. A giant tree (dead) or a coal seam also works. Liquid hydrocarbon sumps could also be viable.