(Ἔμπουσα), a monstrous spectre, which was believed to devour human beings. It could assume different forms, and was sent out by Hecate to frighten travellers. It was believed usually to appear with one leg of brass and the other of an ass. (Aristoph. Ran. 294, Eccles. 1094.) Whenever a traveller addressed the monster with insulting words, it used to flee and utter a shrill sound. (Philostr Vit. Apoll. 2.4.) The Lamiae and Mormolyceia, who assumed the form of handsome women for the purpose of attracting young men, and then sucked their blood like vampyrs and ate their flesh, were reckoned among the Empusae. (Philostr Vit. Apoll. 4.25; Suid. s. v.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890