Will O'Deep

Weakest of the will o'wisp variants, the will o'deep dwells only in the most remote caverns and tunnels. It is a small, flickering spark of energy, usually gold or red, though it can shift to other colors. It can change shape but most often takes a rippling teardrop form that looks exactly like the flame of a little torch. When not attacking, it can dim itself for 2d4 rounds, becoming undetectable to anyone who cannot sense invisible objects.

Will o'deeps speak through changes of color and brightness. A human who survived long enough among them might learn the language, though no one is known to have done so; drow and similar subterranean folk reportedly can follow their conversations.

Mischievous and cruel, the will o'deep loves drawing careless explorers into disaster far from the surface, preferring traps and ambushes to a straight fight. Small groups or clans cooperate to steer adventurers into baffling labyrinths or the lairs of dangerous monsters. Often the goal is not death but exhaustion and imprisonment: a will o'deep may find a spot where a slight push brings down the ceiling or springs an old trap, sealing its victims below for long-term feeding. Explorers who notice one tailing them do well to stay alert, or better, head for the surface.

It can fling up to four tiny white-hot sparks per round, each dealing 1-4 points of damage and strong enough to topple small stones or shove a door shut. It also tends to know where pockets of cave gas have collected. If threatened, it leads pursuers to one and ignites it with a spark; anyone within 10 feet takes 1-10 points of damage, and cave-ins often follow.

Normal weapons hurt it, but magic is nearly useless: only lightning bolt and chain lightning have any effect. It flees once reduced to 25% of its hit points, and if pressed may lead pursuers to buried treasure, hoping the loot distracts them while it escapes.

Will o'deeps live alone or in clans of 2-4 and never venture above ground, staying as deep as their hunger allows.

It feeds on the energy of humanoid minds, particularly the surges produced by fear and desperation. Trapped captives can sustain it for weeks or months, and will o'deeps sometimes even herd rats and other vermin into their prisoners' cells to keep them alive. Once apathy and hopelessness take hold, the creature can no longer feed, so it keeps victims alive only until then. Will o'deeps also sell captives to drow and other dwellers in darkness for gold, gems or fresh prey.