Monday, June 9, 2025

d8 unusual biomes of the underdark

1. Magmatic mustard mangrove
Burning blackened roots curve into asthenospheric lava, and gasping pneumatophores swell erect, back up and out. Sparse leaves are buried beneath blooming yellow flowers, and seed pods of molten minerals and super spicy mustard seed. overipe the seed pods explode like mortar shells at a careless touch, making harvesting them even more perilous. Though the taste is a delicacy prized by affluent gourmands. 

2. Hot spring stairways
Arching limestone stalagnates covered in terraced travertine pools of steaming hot water, they spiral and knot together. The waters are possessed of restorative properties, anyone bathing in a deep enough bowl is treated to an infusion of minerals that strengthen and repair bones. The heat loosens sore muscles and sprains, mends bruising and sweats out toxins.

3. Lungs of the earth
Scalding wind rushes out in bursts of galeforce organ-song from tetraphobic conch shaped stalagmites into the pressurised chambers and tunnels. These are the centrepoints of pneumatotectonic activity, air pressure builds up to breaking point, splitting stone and lifting it up along these fault-lines, creating tremors above and below the earth. Anyone in adjoining tunnels is sure to be thrown off their feet as they are hit by semi regular waves of wind. Continuous inhabatation may lead to nitrogen narcossis. 

4. Radiodated rainforest
lit by glowing rivers of radioactive green soup, this vast chamber is filled with fronded ferntrees smelling like if brusselsprouts strove to be more bitter. Amid the gamma cretaceous foliage and fallout, tumour twisted mutant dinosaurs prowl, descendants of bygone mesozoic megafauna. 

5. Interdidal leech reef
Ocassionaly flooded by stormwater, these tunnels are filled with shallow pools of foetid water contaminated by all manner of runoff and sewage. The walls of the tunnels are meshes of brittle corals that shatter like glass, lacerating the flesh of the incareful. Whenever blood is drawn, lamprey mouthed tube worms the size of boa snakes slurp out of their pipes in the muck and latch onto the wounded creature like that scene from king kong.

https://www.youtube.com/watch?v=xXsqMeSzo1M

 
6. Incubus cap mushrooms
Lurid mushrooms impregnate the air with hallucinogenic spores. Mycelial structures shape themselves into the image of the homes its past victims longed to return to. The spores are very dimly luminescent, providing just enough light for the rods to see but denying colour cones that might help dispel the illusion. It smells like nostalgia, your mothers cooking, your wifes perfume. The longer you stay the more certain you become that you are home and you shouldn’t leave, not ever. Now lie down on that bed of puffballs and rest.

7. Writhing tar cenote
The sound of a hundred hundred flies buzzing can be heard as you drag yourself through waist deep petrol smelling sludge, thicker than molasses. All across your submerged skin you can feel their cola gummy coloured maggoty young wriggling and bitting leaving painful welts behind. In the centre of the chamber beneath the opaque surface is a steep drop off into unknown depths, you will feel a foot plunge deep like missing a stair, if you lack luck your mass will topple into the surface and your face will sink below the sticky morass. Who can say what lurks in that deep well.

8. Magnetospheric ice-age
Twisting walls of cyan ice, lit by micro auroras generated by aberrant magnetic fields. Old ice melts, freezing shut old tunnels and thawing out new ones. Coupled with the compass hating magnetic fields, this is a perilous place to navigate, as one could be drowned or frozen in the waters of a frost thaw. Sinomegaceros chew lichens rapidly growing on the ice and abundant lodestone, fretfully watching for emaciated sabertooths.