monster

Bile-Mutated Troll

CR 7

Large Giant, Chaotic Neutral

Reveal Stat Block

Armor Class

15 (Natural Armor)

Hit Points

126 (12d10 + 60)

Speed

30 ft.

str

dex

con

int

-2

wis

cha

-2

Saves DEX +1, CON +8, WIS +3, CHA -2

Skills PERCEPTION +3, STEALTH +4

Senses Darkvision 60 ft., Passive Perception 13

Languages Giant

Traits

Volatile Regeneration.The troll regains 10 hit points at the start of its turn. If the troll takes fire damage, this trait doesn't function at the start of the troll's next turn. If the troll takes fire damage, it must also succeed on a DC 15 Constitution saving throw or immediately trigger its Aether-Scald Rupture.

Aether-Scald Rupture.When the troll dies, or when it fails its saving throw against fire damage, its pressurized hide bursts. Each creature within 10 feet of it must make a DC 16 Dexterity saving throw, taking 21 (6d6) acid damage on a failed save, or half as much damage on a successful one.

Caustic Splashback.Whenever a creature within 5 feet of the troll hits it with a melee attack that deals piercing or slashing damage, the attacker is sprayed with acidic bile. The attacker must succeed on a DC 16 Dexterity saving throw or take 7 (2d6) acid damage.

Aether-Addict.The troll has advantage on Wisdom (Perception) checks to locate high concentrations of magic (such as leyline nodes or magic items). If the troll starts its turn within 5 feet of a rare or higher magic item, it must use its Multiattack against the creature holding it or spend its action attempting to consume the item.

Actions

Multiattack.The troll makes three attacks: one with its bite and two with its claws.

Bite.Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) piercing damage plus 4 (1d8) acid damage.

Claw.Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage plus 4 (1d8) acid damage. If the target is wearing metal armor, the bile begins to corrode the metal; the target takes a -1 penalty to AC. This penalty is cumulative and lasts until the armor is repaired during a long rest. The armor is destroyed if the penalty reduces its AC to 10.

Bioluminescent Smog (Recharge 5–6).The troll exhales a 20-foot-radius cloud of glowing blue vapor centered on itself. The area is heavily obscured for all creatures except the troll. Any creature that starts its turn in the smog must succeed on a DC 16 Constitution saving throw or be Poisoned until the start of its next turn. The smog lasts for 1 minute or until dispersed by a strong wind.

Bile-Mutated Troll

The Bile-Mutated Troll is a tragic, terrifying testament to the volatile power of the Aethervale’s subterranean lifeblood and the cold orchestration of the Omnisporangium. These creatures were once standard trolls who, driven by an insatiable hunger or displaced by the industrial roar of Steamfort’s Engines, were intercepted by Aether-Weaver Goblins. Through the injection of concentrated Blue Bile, these trolls are forcibly inducted into the Sighing Sickness, triggering a violent evolutionary leap. Their skin is replaced by a translucent, rubbery hide that pulses with a sickly sapphire luminescence, revealing a circulatory system filled not with blood, but with pressurized, caustic magical waste known as Aether-Scald.

In the subterranean ecology, these trolls act as unintended apex predators and the first wave of the Cicadan Swarm. They are the precursors to the dreaded Whisper-Hulks—massive, mobile immune cells designed to "prune" surface stagnation. Caught in a permanent state of "cellular turnover," they wander the Bile-Ducts of Olsa and the Deep-Strands, attracted to the rhythmic vibrations of mining drills and the "sweet" scent of raw Aether. To the hivemind, they are accidental white blood cells—violent, mindless sentinels that slaughter anything attempting to siphon the planet’s cooling fluids.

"The blue... it hums in my marrow. My blood is the scream of the world, and you... you are just cold, dry meat."

Lore & Origin

The transformation is rarely natural. While some trolls stumble into reservoirs of magical waste, most are victims of the Aether-Weaver Goblins' needles. This process, known as Mycelial Threading, weaves fungal filaments through the troll’s nervous system, replacing their natural regenerative properties with a volatile, bile-fueled metabolism. Historically, these mutations peak every 17 years as the Omnisporangium initiates its Equilibrium Cycle. Trolls mutated in this fashion are the "canaries in the coal mine" for a planetary harvest, their presence signaling that the hivemind has begun to view surface civilizations—particularly the Steam Wrights Consortium—as a pathogen that must be recycled.

Secret Motivation

The Bile-Mutated Troll suffers from a permanent state of internal combustion. It does not merely hunt for food; it seeks to dampen the agonizing heat of its own internal chemistry. It is instinctively drawn to high concentrations of Pure Aether, believing that consuming enough of the "Coolant" (Blue Bile) or the "Spark" (Aether) will finally quiet the thrumming agony in its bones. This "Aether-vouring" instinct makes them a primary threat to any industrial site using concentrated magic.

Adventure Hook

Grand Warren-Master Zik-Zik of the Sub-Terran Accord has reported a "Blue-Glow Blockade" in a vital Aether-glass transit tunnel. A massive Bile-Mutated Troll has claimed a pneumatic mail-tube junction as its lair, intercepting sensitive diplomatic canisters between the Accord and the Steam Wrights Consortium. The party is hired to "evict" the creature before its leaking fluids melt through the indestructible glass walls, or before it consumes the Aether-crystals powering the junction.

Sight, Sound, and Smell

The air around the creature crackles with the scent of ozone and the heavy, metallic stench of copper filings and rotting compost. You hear the rhythmic, wet hissing of steam escaping from the pulsating fungal cysts on its shoulders. Visually, the troll is a nightmare of vibrant horror: its muscles are a shimmering indigo, and every time it moves, the gears of its heavy, mutated joints let out a grinding, stony groan. Its translucent flesh reveals the frantic, glowing swirl of blue bile rushing through its veins like liquid neon.

Rumors & Whispers

True: If a Bile-Mutated Troll is slain near a Leyline node, its death-throe explosion can cause a permanent Wild Magic Zone or stabilize a nearby crust rupture.
False: Drinking the distilled bile from a troll's heart grants the consumer the "First Tongue," allowing them to command the Omnisporangium itself. (In reality, it causes instantaneous internal combustion).

Markings

Scratched into the copper-rich walls of the tunnels where these beasts roam, Aether-Weaver Goblins often leave a jagged spiral crossed by three horizontal lines.

Translation: "The Bitter Spring Weeps; Do Not Drink." (A warning that the local water is contaminated with Blue Bile and guarded by a mutated guardian).

Tactics

The Bile-Mutated Troll does not fear steel; it craves the contact. It utilizes a Caustic Splashback reaction, intentionally allowing itself to be struck so its pressurized bile can spray onto attackers, melting armor and flesh alike. In combat, it prioritizes enemies wearing heavy metal armor, as the Blue Bile reacts violently with processed ores, creating a "Magnetic Melt" effect that binds and degrades equipment.

It often begins a fight by rupturing its own cysts to create a Bioluminescent Smog, obscuring the area while it regenerates at an accelerated rate within the toxic cloud. Warning: If the creature suffers fire damage, the internal Aether-Scald undergoes a catastrophic chemical reaction. The troll’s hide ruptures in an explosive spray of acidic gore that acts as a horrific catalyst, accelerating the rapid, chaotic mutation of any nearby flora or fauna caught in the blast.

Ecology

These trolls are "Aether-vores." They no longer digest organic matter in the traditional sense; instead, they filter-feed on the ambient magical radiation of the subterranean depths. They are frequently found near Venda 'Sporelung’s' trade routes. Venda has learned to "herd" them away from her mobile bazaar using low-frequency sonic resonators that mimic the "sleeping" vibrations of the Omnisporangium. However, as the 17-year cycle nears its end, these resonators become less effective, as the trolls begin to sync with the hivemind's aggressive "waking" frequency.

Ideals & Flaws

Ideal: Purity. "The world must be wet and blue. The dry-ones bring the fire; I bring the flood."
Flaw: Aether-Addict. The creature will abandon a tactically superior position or a kill to feast on a dropped Aether-crystal, a glowing magical artifact, or one of Pip the Sun-Spore's unique seeds.