In Tantra, a dharmapala is a type of wrathful deity. The name means "defender of the Dharma".
In Tibetan Buddhism, Dharmapalas (Tibetan drag-gshed) are essentially Hindu gods or Devas, generally believed to have been introduced into Tibetan Buddhism by Padmasambhava in the 8th century. In Buddhist iconography, they are invariably depicted as fearsome beings with many heads, hands or feet; blue, black or red skin; and a fierce expression with protruding fangs. Though dharmapalas have a terrifying appearance, they are all bodhisattvas - embodiments of compassion that act in an extremely wrathful way for the sake of sentient beings.
At least two Tibetan Dharmapala are shared with the Nath tradition, Mahakali (known in Tibetan as Palden Lhamo) and Mahakala. The primary function of Dharmapala, also known as Dharma Protectors, is the protect the teachings of the lineage from appropriation and corruption. Those who would corrupt the tradition risk having their lives interfered with by what are commonly referred to as fierce Himalayan ego-stomping deities.