... During Talmudic times it seems to have been believed that some shedhim were harmless, and, though they were looked upon as evilly inclined and malignant, a friendly intercourse with them does not appear to have been considered contrary to Jewish law.  Thus a Rabbi once assisted in a dispute between two shedhim, in which one who had taken unlawful possession of a place belonging to the other was vanquished and a few drops of blood were found floating on the well where they dwelt (Levit. Rab. 24); but, on the other hand, Abaya saw a seven-headed monster coming out of a well and killed it.*  The attitude of the Rabbis was justifiable so long as it did not lead to real idolatry.
    *This is one of the earliest mentions of a seven-headed dragon, which plays such an important role in fairy-tales. (Encyclopaedia of Religion and Ethics, Hastings, 1916)