This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Baobhan Sith (Celtic Mythology)
The baobhan sith is a female fairy in the folklore of the Scottish Highlands, though they also share certain characteristics in common with the succubus. They appear as beautiful women who seduce their victims before attacking them and killing them. According to the Scottish folklorist Donald Alexander Mackenzie, the baobhan sith usually appears as a beautiful young woman wearing a long green dress that conceals the deer hooves she has instead of feet.
She may also take the form of a hooded crow or raven. One recurring motif in these stories is that the baobhan sith appear almost immediately after the hunters express their desire for female companionship. This is connected with a traditional Scottish belief that if one were to make a wish at night without also invoking God's protection, then that wish would be granted in some terrible manner.