An aged woman of horrific appearance with devilish features, taloned hands and feet, blue-black skin and hair

A Night Hag appears to be an aged woman of horrific appearance, hunched and bent, with devilish facial features, taloned hands and feet, with blue-black skin and hair. They are about the same height and weight as a human female. They are found only singly on the material plane where they search out victims to be slain, taken to the lower planes, and turned into larva (page 152). Night hags prefer the most cruel and selfish of human men as prey, though they will take a woman if she is more cruel and selfish than any man available. When a victim is located, the night hag casts a powerful form of sleep which can affect any creature or character up to 12th-level or 12 hit dice unless a successful saving throw vs. Spells is made. Creatures who would be affected by a normal sleep spell do not receive a saving throw but are automatically affected. A victim who falls asleep will be strangled by the night hag and thus killed automatically, unless someone intervenes to stop her. Any victim who resists the sleep spell is not "in the clear" just yet, for the night hag will visit the victim once they fall asleep normally. The night hag will be in an ethereal (invisible and intangible) state,

Hideous women with clawed hands and feet, dark blue-violet skin, jet black talons and hair, and red glowing eyes

Night hags resemble hideous women with clawed hands and feet. Their skin is dark blue-violet, their talons and lanky hair jet, their eyes red with a baneful glow. Night hags are numerous in their own region of Hades, but seldom found elsewhere. If success seems likely, they will attack any good aligned creature. They come to the material plane to slay very selfishly evil people, whose souls in Hades form soul worms (q.v.: a valuable demonic and diabolical commodity). Finding such a victim, a night hag casts a sleep spell that affects humans even up to 12th level who fail a saving throw vs magic, then strangles the sleeper. If the spell fails, she returns nightly while æthereal, which she can assume at will. By entering the victim's dreams, the hag makes him (or her) æthereal as well. Each ride until dawn by the hag (who cannot be unseated from the unfortunate's back) permanently drains a point of constitution. When all points are drained, the victim dies and the night hag carries the soul to Hades.