Night hag

Night hags are fiends who delight in the corruption of mortals, typically by approaching them in their sleep and filling their dreams with doubts and fears that cause them to turn to evil acts.

Appearance
Exandrian night hags have never been physically described, but in the Monster Manual they have purple skin, black hair, horns, pointed chins, and clawed fingers.

However, they can innately polymorph themselves into a small or medium female humanoid, and at least one night hag frequently uses the appearance of a female fey.

Abilities
The following abilities are all drawn from the Monster Manual, which is the recommended statblock for the night hags mentioned in the sourcebooks:


 * Innate Spellcasting: Night hags can cast detect magic and magic missile at will. Twice per day, they can cast each of plane shift (only on themselves), ray of enfeeblement (+6 to hit, save DC 14), and sleep, all without material components.
 * Magic Resistance: Advantage on saving throws against spells and magical effects.
 * Change Shape: Magically polymorphs into a small or medium female humanoid, or back into her true form, keeping all equipment and statistics. Reverts to her true form upon dying.
 * Etherealness: Switches between the Material Plane and the Ethereal Plane. Must be carrying a hearthstone to perform this action.
 * Nightmare Haunting: While on the Ethereal Plane, the night hag straddles a mortal on the Material Plane and causes visions in that creature's dreams. If the visions last for at least an hour, the creature gains no benefits from the rest and suffers a reduction in maximum hit points until a greater restoration restores them. If this reduces the creature's maximum hit points to zero, the creature dies, and if the creature is evil and the hag has its soul bag, the creature's soul is trapped in the bag for transport to Hades.

Equipment

 * Heartstone: A heartstone is used for the Etherealness ability above, and also cures any disease on touch. Crafting one takes the night hag 30 days.
 * Soul bag: A black sack made of stitched humanoid flesh which requires 30 days and the sacrifice of the humanoid whose flesh is used to make the bag.

History
The Monster Manual describes night hags as once being fey creatures, but they were long ago exiled to Hades and have become fiends. This specific history has not been related in Critical Role media.

As of 812 PD, twin islands in the center of Mooren Lake are blanketed by an ever-present mist, and watched over by a beautiful, ageless woman known only as the Moon Mistress. Local legend has it that she judges mortals who come to her, either killing them or granting them a favor or knowledge. In reality, she is a night hag who takes the guise of a water nymph, and she made sacrifices to keep the mist around to hide herself from a blood hunter named Perron Brill who resided in nearby Drynna.

In their earliest adventures together, the Mighty Nein chased a monster to Crooked Stone, an island in the Ustaloch, but the boatman warned them that no one ever goes there because of the witch who lived there a century earlier and who is rumored to occasionally return to a hovel on the island; that witch is a night hag.

In an adventure hook in the Explorer's Guide to Wildemount sourcebook, set in late 835 or early 836 PD, a powerful night hag leads a coven of hags in the Lotusden Greenwood. They use the blood of children they kidnapped from Charis to fuel an evil artifact that threatens the forest.

Notable night hags

 * The Moon Mistress, a disguised night hag living on the twin islands of Mooren Lake
 * The witch of Crookedstone Island in the Ustaloch
 * Coven of hags in the Lotusden Greenwood, led by a powerful night hag