Heruka is a principal Highest Yoga Tantra Deity (Tantric Buddha), who is the embodiment of indivisible bliss and emptiness.

For a detailed explanation of the practice of Heruka see the book Essence of Vajrayana, and the sadhanas Condensed Essence of Vajrayana, Essence of Vajrayana, Vajra Hero Yoga and Union of No More Learning, and the CDs Songs of the Heroes and Songs of the Vajra Father.