In Tantric Buddhist traditions there are two kinds of deities that appear as wrathful, with flaming hair, bulging eyes, open mouths showing fangs, and garlands of severed heads.
The first kind includes enlightened beings that assume fierce guises to perform protective functions or remove obstacles. Although they may look like demons, these deities are considered wrathful manifestations of wisdom and method. The second kind includes unenlightened, indigenous gods that were incorporated into Buddhism and bound by oath to protect a tradition or lineage of tantric teachings.
