Yamantaka presides over the Eastern direction and is one of the popular deities of Nepalese Buddhist Pantheon. It is said that he is emanation of Bodhisattva Manjushree. With great awesome and virtuous strength, he is capable of subduing poisonous serpent and eliminating countless obstacles.
Bodhisattva Manjushree took this wrathful form in order of subdue the lord of death. So Yamantaka symbolizes the victory over wisdom over death, evil and sufferings. How Yamantaka subdued Yama Lord of Death is described in the legend. It is said that of Bonpo ascetic was just attaining the final stage of his meditative experience after a long years of samadhi. In the mean time a gang of robbers entered his cave in order to slaughter a bull they have stolen. Having cut off the bull’s head they happened to see him and immediately began to attack him. This ascetic begged for mercy but they did not hear his request. They severed his head. All of a sudden this severed head took the form of Yama and fitted the bull’s head onto the place of his own lost head and then massacred the robbers and drunk their blood from the cups made of their skulls. Out of the great rage he even threatened to destroy the whole of Tibet. Then the Tibetans prayed to their protector Manjushree, who then transformed himself into a wrathful appearance of Yamantaka in order to conquer Yama. In the ferocious battle that followed, Yama was subdued. He later determined to become a protector of dharma (thus the name Dharma raja for Yama.)
Among the many forms of Yamantaka, Yamantaka Bajrabhairava is the most popular. He is described in meditational text as follow
Yamantaka Vajrabhairava has 8 heads. The principle head is that of a bull or a buffalo. He has 34 arms and 16 feet to subdue Yama from escaping. On the top of the 8 heads lies the gentle face of golden colored image of Manjushree. His two principal hands hold a skull bowl in a Vajra chopper. The legs are clustered together. His erect phallus has bright red tip. He wears a garland of severed heads, a crown of 5 skulls symbolizing he has the wisdom of 5 Buddhas. Beneath the feet lie the subjugated deities and animals. He is usually depicted with his Prajna.