In Jewish folklore, Lilith is a female demon in some ways similar to a vampire. She derives from a Babylonian-Assyrian demon Lilit, or Lilu. She was believed to have a special power for evil over children. In the Rabbinical literature, Lilith became the first wife of Adam but, being his equal, objected to lying under him in intercourse. When he tried to force her, she flew away.
The ‘Maid of Desolation’ (ardat lili) of Babylonian tradition was a demon of waste places who originally lived in the garden of the Sumerian Inanna. In Assyrian belief, she became a wind spirit, wild-haired and winged. In the Talmud, Lilith is a succubus-a demon of the night whose offspring, from her unions with men, became demons. Attacking men who slept alone, she was an angel of darkness, becoming a goddess of conception. This belief gained strength in the Middle Ages. It was said that children in their first week of life were most susceptible to Lilith, although some said a girl was in danger for twenty days and a boy was in danger for the first eight years of his life.
A talisman of protection against Lilith had to have three names engraved on it: Sanvi, Sansanvi, Semangelaf. These three names could also be written on the door to a child’s room. To medieval Jewry, Lilith was the one that caused men to have nocturnal emissions. Her offspring were the lilin, or lilim, and were said to have human bodies but with wings and the hindquarters of a donkey, although a terracotta relief from Sumer depicts Lilith herself as a human but with wings and the taloned feet of a bird. Lilith also appears in the folklore of Britain, Greece, Germany, Mexico, and even Native American legends.
-excerpt from The Witch Book (The Encyclopedia of Witchcraft, Wicca, and Neopaganism) by Raymond Buckland.
Sources: Leach, Maria (ed.): Funk & Wagnalls Standard Dictionary of Folklore, Mythology, and Legend. Harper & Row, 1984.
Leland, Charles Godfrey: Etruscan-Roman Remains. Unwin, 1892.