This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Black Annis (English)
Black Annis (also known as Black Agnes or Black Anna) is a bogeyman figure in English folklore. She is imagined as a blue-faced hag or witch with iron claws and a taste for human flesh (especially children). She is said to haunt the countryside of Leicestershire, living in a cave in the Dane Hills with a great oak tree at the entrance.
She is said to venture out at night looking for unsuspecting children and lambs to eat, then tanning their skins by hanging them on a tree before wearing them around her waist. She would reach inside houses to snatch people. Other traditions stated that when she ground her teeth people could hear her, giving them time to bolt their doors and to keep away from the window.