Brox

In Jewish folklore, a witch is a werewolf, sucking blood from people. Broxa could change her shape as she wanted. Sometimes she was described as a spirit devoid of flesh, sometimes — on the contrary, as a creature of flesh.

In the medieval Portugal Brox was considered a shape—shifting entity-a witch in female form and a demon in male form. It has been suggested that this creature originated from the same Jewish mythical creature. 

Sometimes the option is indicated that this is a bird that sucks goat's milk at night, and sometimes human blood.