Dharma Protectors (Skt: dharmapala, Tib: chos kyong) is a wrathful deity, pledged to defend the Dharma, its practitioners, etc. Dharmapalas often have blue, black or red skin, and a fierce expression with protruding fangs. Though dharmapalas have a terrifying appearance and countenance, they are all bodhisattvas or buddhas, meaning that they are embodiments of compassion that act in a wrathful way for the benefit of sentient beings.
In the Yamantaka/Vajrabhairava practice one relies on four dharmapalas: (1) Kalarupa, (2) Mahakala, (3) Palden Lhamo, and (4) Vaishravana.
Yama Dharmaraja, also known as Kalarupa (Tib: gshin rje chos rgyal; = the Lord of Death, King of the Law), is one of the Dharma protectors of the father class of Anuttarayoga Tantra, in particular for the Vajrabhairava tantras. Although Kalarupa is found in all the Sarma Schools the Gelugpa tradition holds Yama Dharmaraja in special regard as one of the three main Dharma protectors of the School - along with the Six-Arm (Shadbhuja) Mahakala and Vaishravana. These three were the special protectors of Lama Tsongkapa.
With one face and two hands, dark blue in color, the head is that of a buffalo, three round eyes, sharp horns entwined with flame, fierce and angry. Held upraised in the right hand is a bone stick composed of a fused spine and skull. In the left hand is a coiled lasso. Adorned with a crown of skulls and bone ornaments, he wears a necklace of fifty freshly severed heads. Appearing extremely animate he stands with his right leg bent and the left extended on the back of a buffalo above a human body and lotus seat. He is usually accompanied by his female consort Chamundi who is blue in color, with one face and two hands. A trident is held aloft in the right hand and a skullcup in the left. Both are adorned with wrathful attire, bone ornaments and various skins, completely surrounded by the swirling orange flames of pristine awareness.
There are three forms of Yama Dharmaraja: Outer, Inner, and Secret. Inner and Outer Yamaraja are blue/black, the Secret Yamaraja is red in color.See the gallery for the differences.
This dark-blue/black form of the six-armed (Skt: Shadbuja) Mahakala (also called "Nagpo Chenpo", Tib: gnag po chen po; or by the Tibetans just "lord", Tib: mGon po) was originally brought to Tibet by Khyungpo Naljor, the founder of the Shangpa Kagyu School. It became popular in the Sakya and Kagyu traditions and was later adopted into the Gelugpa School, becoming the principal protector. There is also a White Six-Armed Mahakala (Skt: Shad-bhuja Sita Mahakala; Tib: mGon po yid bzhin nor bu) popular among Mongolian Gelugpas and the Shangpa Kagyu School.
"The Lord of Pristine Awareness has six hands and a body dark blue in colour. The first two hold a curved knife and skullcup, the middle two a human skull mala and trident, the lowest two a damaru drum and lasso. Adorned with a tiger skin, garland of heads, bones and snakes, and small bells on the hands and feet. Standing in a manner with the two legs together pressing down on Ganapati. With three eyes, bared fangs, eyebrows, beard and hair flowing upward with Akshobhya as a crown. Anointed with a sindhura drop on the forehead. Supported behind by a sandalwood tree, dwelling in the middle of a blazing mass of fire." (Jonang Taranatha, 1575-1634).
The wrathful deity Palden Lhamo (Tib: dpal ldan lha mo, or dMag zor ma rGyal mo; Skt: Shri Devi or Remati) is one of the main Dharma protectors in the Gelug school of Tibetan Buddhism and considered to be the the tutelary deity of Tibet and its government", and as "celebrated all over Tibet and Mongolia, and the potent protector of the Dalai and Panchen Lamas and Lhasa."
The detailed iconography of Palden Lhamo is complicated, and this is not the place to discuss it. Jeff Watt wrote an excellent article on the Himalayan Art site about it. In the context of the Gelugpa school of Tibtean Buddhism we deal specifically with the form of Magzor Gyalmo (Tib: dMag zor ma rGyal mo) meaning "Glorious Goddess, the Queen who Repels Armies", or "the Queen who has the power to turn back armies". She has a blue-black body and and a fiercly wrathful expression, has one face and two hands, holding aloft with the right hand a vajra-tipped staff and in the left a skullcup held to her heart. She rides on a side-saddle atop a mule. Above her head is a large peacock feather parasol.
Vaishravana (Tib: rnam thos sras) is one of the three principal Dharma protectors (dharmapalas) of the Gelug school of Tibetan Buddhism - the others are Yama Dharmaraja (Kalarupa) and Six-Arm (Shadbuja) Mahakala. He is also known (1) as the King or Guardian of the North and (2) as a god of wealth.
He is usually portrayed with a stern look and two large staring eyes, one face and two hands. In his right hand he holds a victory banner of variously coloured fluttering silks - a gift of the gods, and with his left he holds a black mongoose spitting a flood of colored jewels collecting on the moon disc below. Adorned with a gold and jewel crown, earrings, body armour of gold, garments of various colours, pants and boots, he sits in a relaxed posture with the right leg extended atop a snow lion.