This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Bi-blouk (Khoikhoi)
In the folklore of the Khoikhoi, there are a people, human-like but not human, who literally live half in our realm and half in another, manifesting as a half-bodied entity, the Hai-uri (male) or Bi-blouk (female). They are said to be fierce and able hunters of humans, but there are stories of them living among and even marrying them as well. They are sometimes described as a Female, cannibalistic, partially invisible monster.