Mahakala is a wrathful deity from the pantheon of Tibetan Buddhist gods in the Vajrayana tradition.  He is a protector of the doctrine (dharma) and also assists the devotee in overcoming his ego.  Shown here in his four-armed form, he holds a skull cup (kapala) and sword with his inner hands, a ceremonial staff (khatvanga) in his far left hand, and with raised index finger makes the gesture of warning (tarjani mudra) with his far right hand.  The circle of flames represents his ability to burn up negativities. 

There are many forms of Mahakala with differing numbers of arms, holding differing implements, having differing functions, and being associated with various lineages.  He appears here as the central image, but he is also often is included as an accessory figure in more complex compositions. The origins of Mahakala lie in India, and probably with Shiva as is shown by Mahakala’s ceremonial staff topped with a trident, one of Shiva’s emblems. There are a number of documented stories of sages encountering various forms of Mahakala in Indian cremation grounds and bringing them to Tibet. This image was taken from a 13th century Tibetan painting (thanka).