A Slip Skin Hag (Boo Hag), is a combination witch/vampire/demon of folklore in the Southern portions of the United States, especially among those of Gullah descent as well as believers and practitioners of Hoodoo.
A Slip Skin Hag appears as a normal woman by day but by night slips out of her skin and flies around in search of victims to torture and harass while they sleep. Victims are said to experience sleep paralysis, awaken with strange scratches, suffer from nightmares, and are plagued with unnatural illnesses and fatigue, often leading to mental illness and eventually death. Slip Skin Hags are also said to press on their victim's chest while they sleep in an attempt to suffocate them. Such a state is referred to as being 'hag ridden'. If the victim is male, sexual molestation may occur.
A Slip Skin Hag is distinct from a traditional Hag, mainly due to the fact that by day Slip Skin Hags appear and act as normal human women. (A traditional Hag is a spirit-like entity.)
Appearance: By day a Slip Skin Hag appears as a normal human woman. At night, the Slip Skin Hags slips out of her skin and searches for victims. Fortunately she remains invisible when out of her body, though it is said that if one attempts to wrestle a Slip Skin Hag, and could grab hold of her, then one would feel the sensation of holding raw meat.
Lore: Just as in traditional Vampire legends, the Slip Skin Hag must return to her skin by sunrise or else she will die. Unlike the traditional Vampire who drinks blood, the Slip Skin Hag feeds off of the soul, breath, or life-force of the victim.
Powers: Invisibility, flight, can pass through the tiniest cracks or spaces in order to enter into the bedrooms of her victims, with keyholes being a well known entry point.
The book, Blue Roots: African American Folk Magic Of The Gullah People by Roger Pinckney, documents (p.78) a reported Slip Skin Hag in Charleston, SC, in 1916:
"Neighbors suspected a certain woman of going out after dark and tormenting a former lover who had found a new partner. They found the skin hanging behind the woman's bedroom door, salted it thoroughly, and waited anxiously in the closet. The woman came in at dawn, commanded the skin back into it's rightful place. The skin, in salty misery, did not respond. "Skin, skin, don't you know me?", the woman pleaded. The neighbors leaped from the closet and the hag disappeared into thin air, never to return."
Defense Against Slip Skin Hags: A Slip Skin Hag can be killed if she doesn't return to her skin by sunrise or if her skin is destroyed while she is out of it. Another method of inflicting suffering or death upon a Slip Skin Hag is to salt her skin so that it causes extreme pain when it is placed back on her "raw" flesh. (Red Pepper is also said to work wonders as well.) If a victim knows the identity of the Slip Skin Hag he can write her name as well as the word 'Hag' above his front door and this will bar her from being able to enter. 'Direct Confrontation', i.e. publicly accusing the suspected Slip Skin Hag is also said to rob her of her ability to harm. Other methods of repelling Slip Skin Hags refer to Vampire lore, mainly by hanging a kitchen sieve over the bed or by scattering sesame seeds on the floor around the bed. (The Slip Skin Hag must count each hole in the sieve and each sesame seed before she can attack the victim, thus making sure sunrise will come before her task is complete.) Other methods include magic itself. Hoodoo men and woman, a.k.a. root workers, root doctors, or conjurers, can use rituals and magic to repel, kill, or even trap a Slip Skin Hag in the form of an insect in a bottle. The insect is then killed and the hag is destroyed.
Wicked Charleston by Mark R. Jones
Her Stories by Virginia Hamilton, Leo Dillon, Diane Dillon