The wrathful deity usually shown as black or dark blue, serving as a dharmapala and often wearing a tiger skin, is Mahakala.
Mahakala means “Great Black One” and is a major protector of the Dharma in Vajrayana Buddhism. His frightening appearance—flaming hair, fangs, skull ornaments, and a garland of severed heads—represents uncompromising compassion that destroys obstacles to practice, not hatred or ordinary violence.
Mahakala exists in many forms, including two-armed, four-armed, and six-armed manifestations. Attributes vary by tradition, but common objects include a curved ritual knife and a skull cup. The tiger skin frequently worn around his lower body symbolizes the transformation or purification of desire.
Mahakala should not be confused with Yamantaka, the buffalo-headed conqueror of death, or Vajrapani, whose defining emblem is the vajra. The name and imagery also overlap with Hindu traditions, where Mahakala is a fierce form of Shiva; Buddhist traditions reinterpret him as a guardian of Buddhist teachings.