Bastellus

Called a nightmare or dream stalker in many lands, the bastellus is an undead horror that feeds on the dreams of sleepers and appears only around them. Those who interrupted a feeding describe a hulking, featureless human-shaped shadow with a hand laid on the victim's forehead and its head tipped back in rapture. No one has ever spoken with one, and whether it has a language is unknown, yet people it visits sometimes wake knowing facts they never learned.

Only +3 or better weapons touch it, and they deal half damage. Charm, sleep, hold, poison, and cold, heat or electrical spells fail against it. Holy water does nothing, but powerful priests turn it as a ghost. The one reliable way to destroy it is dispel evil cast directly on it, and it still gets a save vs. spells. Protection from evil bars it from an area or person without harming it; negative plane protection blocks it entirely and ends its compulsion to revisit that victim.

In shadow it goes unseen 95% of the time; even a wary watcher spots it only with a percent chance matching his better score of Intelligence or Wisdom. Entering a room of waking folk, it casts sleep on all within 50 feet, who save at -4; elves resist only 30% and half-elves 10%. That sleep is dreamless, so it feeds only on those already asleep before the spell, and never on elves or half-elves.

Its touch on a sleeper's brow turns the dream into a vision of his deepest fears, such as a paladin's chaste beloved becoming a temptress whose embrace means damnation. He wakes shaken, regains no hit points, cannot memorize spells or concentrate deeply, and is one level lower. Drained below level 0, he dies seemingly of heart failure, and unless the body is burned, dissolved in acid or otherwise destroyed, rises as a new bastellus after as many days as levels lost (two weeks for a 14th-level wizard).

Caught awake, it flees; its sleep fails on anyone who sees it. It can create darkness within 50 feet, which defeats magical light below 3rd level but not continual light, and pass through solid matter. Bright light does not harm it but keeps it out, though it may still cast sleep into a lit area from close by. Forced to fight, it moves through a living foe on a normal attack roll, and the target must make a saving throw vs. spells or for 1d4 rounds see his allies as mortal enemies and attack them.

At 0 hit points without dispel evil it boils away like steam, its telepathic shriek forcing a fear check within 50 feet; a dreamer it was touching must save vs. death or die. The next night it returns to the spot where it first arose. Its days pass in a pocket realm of shadow and nightmare that restores all its hit points before dusk.

It haunts towns and cities, choosing the most vivid dreamers: passionate, driven or creative people, often well known, whose sudden deaths cause alarm. After one taste it returns nightly until that victim dies, then moves on. A newly risen bastellus remembers nothing and must feed before its first night ends or fade forever. Scholars think its pocket realm blends the negative material plane with the misty dread realm, the only place bastelli are found.

Some deny it any place in nature; others believe it grows from the unspoken hopes of the living. The debate has run for centuries unresolved. Its dream substance is nearly priceless to necromancers and illusionists, and a speck of it in an illusion makes the images almost impossible to disbelieve.