Mother Yasoda was firmly convinced that she should protect her child from different kinds of evil spirits and ghosts — namely Dakinis, Yatudhanis, Kusmandas, Yaksas, Raksasas, Vinayakas, Kotaras, Revatis, Jyesthas, Putanas, Matrkas, Unmadas and similar other evil spirits, who cause persons to forget their own existence and give trouble to the life airs and the senses. Sometimes they appear in dreams and cause much perturbation; sometimes they appear as old women and suck the blood of small children. But no such ghosts and evil spirits can remain where there is chanting of the holy name of God.

(From Srila Prabhupada's Krsna Book, ch. 6: Putana Killed)