So, the morlocks of the hollow earth are invading the surface world. They believe, quite correctly, that ancient treaties give them dominion over the human kingdoms.
There are billions of them down there, teeming in the tunnels like a pumpkin full of maggots. But getting there is a year-long journey through the bowels of the earth, and through a very literal hell. (The mythic underworld of Centerra is a literal underworld.)
So, to facilitate that horrible journey from their watery blue sun (through ghosts and gravity and magma) they built the drill cities, which they can ride through the earth until they emerge onto the surface of Centerra and feel the cruel warmth of its alien, yellow sun.
Like all good disasters, they will be heralded by earthquakes.
When they get really close--less than a week--you can taste them in the drinking water.
And then the thing is peeking through the ground some morning, like the fontanel of some unborn beast, spiraling out of the ground. It grows 10 feet taller every minute, forming a narrow tower like a unicorn's horn or a broad, low spiral like a seashell.
The walls are striated steel, gouged where the fossil demons tried to get in and polished where semi-molten rock has abraded it. Compared to the squares and triangles of human architecture, the blunt spiral of the morlock drill-arcology is completely alien.
The usual tactic is to overwhelm an adjacent city in the space of a few days by launching night time raids. If that doesn't yield the immediate results, they'll begin tunneling under the human settlement. Morlocks dig fast.
Population of Drill City?
- 1d6 x 300 morlocks
- 2d10 derro saboteurs
- 2d8 fomorian giants
- 2d6 chelinausca overlords
- 25% chance of an illithid ambassador
- 25% chance of a beholder mercenary
- 25% chance of sentient, obedient purple worm
- 25% chance of a deep dragon
State Upon Arrival (d6)
- Orderly, disciplined, well-stocked.
- Still orderly and under control, but desperate for food.
- Panic and starvation among the overlords, half of the population has been eaten, more like refugees than an army (still well-armed, though).
- Overlords dead, morlocks have regressed into hyper-agressive, feudal state.
- Overlords dead, morlocks have regressed even further, lord of the flies, primitive system, half-mad from metal, centrifugation, and hunger (they have not forgotten how to use their weapons).
- Everyone dead due to some disaster, roll on derelict drill hulk table below.
Derelict Drill Hulk (d4)
- Death caused by catastrophe involving their superweapon (roll below).
- Undead breached the hull. Full of zombies, ghouls, and wights. Led by a serpent made of fused corpses (HD 10) that breathes a cone of necrotic rot-bolts and zombies (active).
- Cooked in the lava. Filled with cooked meat. Completely deserted except for a huge black pudding (HD 16), currently half-baked onto the floor of the plaza, but will wake up after walked on a couple of times.
- Demons. 2d6 of them, puppetting hapless morlocks around like fuckin' skincars. Once it exits its morlock, the lead demon is sort of an anti-medusa (humans growing out of a snake) possessing a gaze attack (save or be turned inside out).
Chelinauscan Overlords (d3)
- Pax Churubin, MU7, dark purple shell, possesses a ring of acid immunity, a ring of no breath, and an amulet of ooze control. Rides around inside a gelatinous cube.
- CalasYakekerker, MU6, crimson shell inscribed with raw madness (headaches if glanced at, save vs insanity if actually read), possesses a harem of giants
- Chindurian Sacroplex, MU8, shell such a dark red that it is nearly black, is secretly a lich. He hides his lichdom with a complicated system of perfumes.
Morlock Masterslaves (d3)
- Bleedak Hollowman, F6, a sphere of annihilation follows him around like a loyal dog (albeit a disobedient one).
- Scrivener Terrok, T8, has a cloak of dimension door (1/day) and a wand of centrifugation (save or be spun around in increasingly terrifying rpm, like hold person except you take 1d6 damage per turn (cumulative/stacking) has 8 charges left).
- Trembler Ulura, MU7, wears blue smoke for clothing, poisonous fingernails, capable of casting a version of maze that allows the caster to enter the labyrinth as well (allowing her to challenge people 1 v 1 and kill them in the maze space).
Secret Superweapon (d6)
- Stable of purple worms, kept docile via vast quantities of under-opium.
- Plague stirges.
- Bethorem, fallen goddess of hailstorms (HD 9), currently trapped inside a flailsnail shell in a tank of acid. She can be used to summon baseball-sized hail.
- Mechanical beholder tower firing pencil-thin rays of disintegration. Will be used to cut buildings in half and write discouraging messages on mountainsides.
- The demon Goldenlight (HD 8, regenerates 5 hp/round, all damage he takes is duplicated on the person who attacks him) who appears as a fat (nearly spherical) morlock covered in jewels and red silk. He is a shapechanger with access to charm person--he will destroy the humans from within.
- Drill city is actually the shell of a giant cone snail that breathes vast clouds of poison. Controlled by morlocks living in its hat.
- Time machine.