In India, there is a type of vampiric spirit that is known as a mukai. Created when a woman dies in childbirth or by some other unnatural way, it is easily detected for what it is, as the feet of a mukai are turned backward. At night, it attacks the men in its family first, draining them of their blood before moving on to others. If a mukai should give a man a piece of food and he accepts it, by morning all his HAIR will have turned white.

Source: Bombay State, Gazetteer of Bombay State, vol.20, 125; Crooke, Introduction to the Popular Religion, 168; Crooke, Religion and Folklore, 194; Jones, On the Nightmare, 119