Black Annis is a ghost of British folklore, said to haunt the hills of Leicestershire. This is from my Time Life Books Enchanted World series, the volume titled Night Creatures:
Said to be a descendent of an ancient, bloodthirsty goddess, Black Annis was one-eyed, livid-faced and long-clawed. She haunted the Dane Hills and, at twilight, crouched in an old oak tree. This tree, the last vestige of a forest that had covered the land before history began, evidently gave her special shelter. She waited patiently for passersby, but her special victims were children. These she flayed alive with her curving claws. The tender flesh she ate, but the pathetic little skins she took to a cave in the hills -- known, with mordant humor, as Black Annis' Bower -- to hang on cold stone walls as trophies of a triumph of the old world over the new.
According to pantheon.com, "Every year on Easter Monday, it was customary to hold a drag hunt from (Black Annis's) cave to the Mayor's house. The bait was a dead cat drenched in aniseed." Sounds like fun.
It has been suggested that the Black Annis legend is based on that of an old Celtic fertility goddess Anu. This is from britannia.com:
Anu was known, in the Celtic World, by several similar names: Danu or Don being the most popular alternatives. She was a Mother-Goddess, the wife of the Sun God, Belenos, and considered to be the ancestor of all the Gods. . . She still looks down on us from the night's sky where she appears as Llys Don, better known as the constellation of Casseopeia. Anu was especially popular in Munster, though her most lasting memorial is a mountain in County Kerry called the Dá Chích Anann or "Breast of Anu". The Dane Hills in Leicestershire are also named after her and this area, perhaps a major centre for her cult, is where her memory lives on as Black Annis. This hideous old crone's habit of eating young children was, no doubt, invented by incoming Christians to blacken the name of the Celtic Goddess.