There are some types of living entities in the form of human beings whose living conditions and eatables are most abominable. Generally they eat flesh and fermented blood, which is mentioned in this verse as ksatajasavam. The leaders of such degraded men known as Yaksas, Raksasas, bhutas and pisacas, are all in the mode of ignorance. They have been placed under the control of Rudra. Rudra is the incarnation of Lord Siva and is in charge of the mode of ignorance in material nature. Another name of Lord Siva is Bhutanatha, meaning master of ghosts. Rudra was born from between Brahmas eyes when Brahma was very angry at the four Kumaras.