ECOLOGY

Environment any
Organization solitary, pair, or horror (3–5)
Treasure none

Trench mists are created anywhere that deadly gas attacks are used for the wholesale slaughter of troops, whether attacks of a mundane poisonous nature, or from the magical effects of spells such as acid fog. Under mysterious circumstances likely born of the horrors of war and the final throes of young soldiers dying before their time, these mists linger over the battlefield, absorbing the departing souls of the slain. This commingling of loosed life energy and strange chemicals grants the miasma a sly, malevolent sentience. Once so born, the trench mist then seeks only to impart misery and share its singular fate with those fortunate enough to have escaped the poisonous attacks that birthed the creature in the first place. As it preys upon the living it absorbs the afflicted into its growing horde of shambling servants. Victims of its acidic mist rise as hateful zombies under the creature's control, and a trench mist that gains a horde of zombies is a dangerous foe indeed. On battlefields where trench mists are known to have arisen, wise commanders arrange cease-fires during which both sides abandon the site, lest their troops succumb to the horrifying fate of their comrades.

Part of the trench mist's self-awareness comes from the symbiotic trench zombies it gains as it slaughters its victims, as the zombies under the mist's control retain the abilities they had in life as well as some snippets of their former memories, which all feed into the collective consciousness of the trench mist. This allows the mist to learn and adapt, granting it a relatively keen intelligence compared to other similar creatures, and allowing it to make canny combat decisions and cleverly manipulate its surroundings.

Trench mists wander battlefields looking for prey so they can add more shambling zombies to their collective hordes. Occasionally they might even enter inhabited areas to seek out fresh ammunition and armaments for those of their symbiotic undead who may have exhausted their weaponry. When bereft of such foul company, trench mists often persist for years after the tides of war have receded, settling into the soil and slumbering until fresh prey arises. The lifespan of trench mists is unknown, though through this sort of hibernation they very well may be immortal, reemerging without warning at the scenes of ancient battles centuries after they have taken place, whether turned up by an unsuspecting farmer's plow or war waged anew.