Heruka, is the name of a category of wrathful deities, enlightened beings in Vajrayana Buddhism that adopt a fierce countenance to benefit sentient beings.
In East Asia, these are called Wisdom Kings.
Herukas represent the embodiment of indivisible bliss and emptiness.
They appear as Iṣṭha-devatā or meditational deities for tantric sādhanā, usually placed in a mandala and often appearing in Yab-Yum.
Heruka represents wrathful imagery with indivisible emptiness (śūnyatā), bliss, peace, wisdom, compassion (bodhicitta), and love. .