A description of the earliest iconography of Tantrism is given below – Shiva and Rudra being Herukas – “Heruka (Sanskrit; Tib.khrag ‘thung), is the name of a category of wrathful deities, enlightened beings in Vajrayana Buddhism that adopt a fierce countenance to benefit sentient beings. In China and Japan, it was named as Wisdom King. Herukas represent the embodiment of indivisible bliss and emptiness. … The name “Heruka” is made up of the prefix “he-” meaning “hey!” and “ruka”, a rich term implying many levels of subtle meaning – richness, royalty, etc….The Sanskrit term Heruka was translated into both Chinese and Tibetan as “blood drinker,” which scholar Ronald Davidson calls “curious,” speculating that the nonliteral translation derived from an association the term has with cremation grounds and ‘charnel grounds’ (Sanskrit: śmāśāna) (which absorb the blood of the dead). Sanskrit terms for blood drinker include asrikpa, reflecting a Sanskrit word for blood (asrik), and raktapa, raktapayin, or rakshasa, derived from an alternate root term for blood (rakta). Unlike the Chinese and Tibetan (Tratung, wylie: khrag ‘thung) terms used to translate it, the Sanskrit term heruka does not literally mean blood drinker…”
Excerpt from Genesis and Development of Tantrism
the Heruka* of the Sarvabuddhasamdyoga. He is black-bodied, and has twelve arms and four faces, with three eyes in each. He stands in the warrior pose with a Vajra and a Vajra-topped bell in his two principal hands, holding the bleeding hide of a flayed elephant over his back with his two uppermost hands, and in the remaining eight a rattle-drum (damaruh), a battle-axe, a chopping knife, and a trident, a skull-topped staff (khatvdngah), a skull-bowl (kapdlam) filled with blood, a lasso (pdsah), and the severed head of the god Brahma, wearing a long garland of fifty bleeding human heads around his neck, adorned with five ornaments of human bone and the ash of cremation-pyres smeared over his limbs — these, the bone ornaments and ash, are the Six Mudras of the Kapalikas — , with a tiger skin around his waist, a brahmanical cord in the form of a snake (ndgayajnopavltah), and a chaplet of skulls (kapdlamdld) above his forehead, his hair arranged in a high crown-like mass of ascetic’s braids (jatdmukutah) adorned at the front with two crossed Vajras (visvavajram) and the new moon. His consort Vajravarahi stands before him in sexual union, with Heruka holding her to his chest with the hands that hold the Vajra and the Vajra-bell crossed at the wrists behind her back. She is red, one-faced, and two-armed, naked but for a filigree of fragments of human bone adorning her hips (asthimekhald), her right arm raised aloft holding a chopping-knife, with her index finger extended in a gesture of threatening the wicked, and her left arm, wrapped around Heruka’s neck, holding to their mouths a skull bowl full of human blood and entrails, wearing a garland of fifty desiccated heads and the five Kapalika bone-ornaments, laughing, and intoxicated by lust. They are surrounded by a retinue of thirty-six goddesses termed Yoginis, Dakinis, Viresvaris, or Virinis visualized in the same Kapalika style, in concentric circuits of four, twenty-four, and eight, the twenty-four embracing Vira consorts and worshipped as residing in twenty-four sacred sites covering the whole subcontinent, from Uddiyana in the north to Ramesvara at India’s southern tip, from Sindhu in the west to Devikotta in the east. The whole is surrounded by a ring of eight cremation grounds. 400
The features of Siva’s iconography evident here are the trident, the third eye, the new moon on the piled up braids, the tiger-skin lower garment, the multiple faces and arms, the skull-bowl, the skull-staff, the bleeding elephant hide, the severed head of Brahma, the snake as brahmanical thread, the sharp fangs, the chaplet of skulls, his dwelling in the cremation grounds, and the ashes 400 This description of Heruka and Vajravarahi follows that given by Jayabhadra in his Cakrasamvarapahjika, p. 109, on Laghusamvara 1.10. for the iconography of the Yoginis and Viras see Bhavabhatta’s Cakrasamvaravivrti on Laghusamvara, Patala 4 (vol. 1, pp. 44-47). See also Nispannayogdvali, pp. 26-29.-170-
The Saiva Age
on his limbs. All these had entered Siva’s iconography long before the forma-tion of the Tantras of the Cakrasamvara cycle. Siva’s trident appears on seals and intaglios during the Kusana and Kusano-Sassanian periods in Gandhara and Afghanistan. 401 The third eye appears in sculptures of Siva from Mathura around the beginning of the third century; and the ascetic’s piled braids and the new moon upon them appear there and elsewhere from the beginning of the fifth; 402 and all these characteristics, the trident in his hand, the third eye, the ascetic’s braids, and the new moon, are mentioned in the Mahabharata, 403 as are his tiger-skin, his multiple faces and arms, his skull-bowl, his skull-staff, his brahmanical thread in the form of a snake, his sharp fangs, his garland of skulls, and his living in the cremation grounds smeared with ashes from its funeral pyres. 404 His wearing a bleeding elephant hide is also a commonplace by that time, being mentioned along with his crematorial characteristics in the works of the poet Kalidasa. 405 As for the severed head of Brahma, this too derives from a well-known Saiva myth which though not found in the Mahabharata in the text common to all the regional versions, 406 does appear in the Skandapurana-401 For a recent analysis of Siva images in the subcontinent, including those on coins, from the first century B.C. to the end of the Kusana period, see Ghose 2002, pp. 70-96….
405 Meghadiita 36c: hara pasupater ardrandgajineccham ‘Remove Siva’s desire for his [blood-]wet elephant hide’; Kumarasambhava 5.67d: gajdjinam sonitabinduvarsi ca ‘[his] elephant hide that showers drops of blood’; 5.77b: trilokanathah pitrsadmagocarah ‘The Lord of the Three Worlds frequents cremation grounds’; 5.69c, 5.79b: citabhasmarajah ‘the ash-dust of funeral pyres’; and 5.71b: kapdlinah ‘decked with skulls’. Rudra/Siva frequently has the epithet krttivasas- ‘wearer of the hide’ in the Mahabharata. The Matsyapurana (Patala 153) relates that this is the hide of the elephant demon Gajasura killed by Siva in a great battle between the gods and the Asuras. How the elephant hide was understood when incorporated into the iconography of Heruka is not stated in most instances of its mention. But in two Kalpas in the Abhidhanottara, those of Samayasamvara and the Heruka of the ekaviravidhanam, it is said to be that of the elephantine Saiva-brahmanical deity Ganapati (B f. 34vl…
On Rudra’s connection to Shiva/Siva, see How Shiva Got The Name ‘rudra’
Shiva, the destroyer, is one of the three supreme gods in Hindu mythology. The other two are Brahma, the creator, and Vishnu, the preserver. Shiva’s destructive powers are awesome, but they also have a positive side in that destruction usually leads to new forms of existence. In art, Shiva is often portrayed with four arms, four faces, and three eyes. A glance from the third eye in the center of his forehead has the power to destroy anything in creation, including humans and gods. In the Vedas, a collection of ancient sacred texts, Shiva is identified with the storm god Rudra.
Birth of Shiva. According to one myth, Shiva first appeared when Brahma and Vishnu were arguing about which of them was more powerful. Their argument was interrupted by the sudden appearance of a great blazing pillar whose roots and branches extended beyond view into the earth and sky. Brahma became a goose and flew up to find the top of the pillar, while Vishnu turned into a boar and dug into the earth to look for its roots. Unsuccessful in their search, the two gods returned and saw Shiva emerge from an opening in the pillar. Recognizing Shiva’s great power, they accepted him as the third ruler of the universe.
Roles and Powers. Shiva is a complex god with many roles and powers. In his destroyer role, he often haunts cemeteries, wearing a headdress of snakes and a necklace of skulls. A band of terrifying demons, hungering for blood, accompanies him. … Read more here and Indo-European Deities and the Rigveda by N. D. Kazanas and also Proto-Indo-European religion for correlations between PIE and Vedic deities.
The ancient Vedic people worshipped a fierce celestial deity of storms, known as Rudra, who, according to many scholars, was none other than a prototype of Lord Shiva. Rudra being an epithet of Shiva, both are viewed as one and the same in Hindu tradition. Rudra means the one who is red or fierce. The ancient Vedic Indians feared Rudra for his ability to cause death and disease. They also revered Him for his ability to protect people from sudden death and snake bites. The Vedic hymns described Him as the god of roaring storms and ancient healer. The Rigveda (2.33) describes Him as the “Father of the Maruts”, a group of storm gods. One of the most sacred hymns of the Vedas is Rudram, found both in the Rigveda and Yajurveda, which invokes Rudra and mentions the name Shiva several times, not in the current sense but as an epithet of Indra, Mitra and Agni.
The Rigvedi hymns describe Rudra as as Sarva (the Archer), a name by which Shiva is also known popularly and name which alludes to his conneciton with ancient non-Vedic tribes. It is also included as one of His 1000 names, which are used in his ritual worship. In the Mahabharata, Shiva appears to Arjuna as an archer only. The name Sarva, means the one who injurs or kills, the same attributes with which Rudra is deified in the Vedas.
Identification with Vedic deities
In the Vedic literature, Shiva was closely identified with other Vedic deities such as Agni, Indra, Prajāpati, Vāyu, and others.
According to some scholars, the identification between Agni and Rudra in the Vedic literature was an important factor in the process of Rudra’s gradual development into the later character as Rudra-Shiva.. the Nirukta, an ancient text of Sanskrit etymology, draws the connection between the two, saying Agni is also Rudra. Agni being the sustainer as well destroyer of life, the connection between the two is inevitable. According to Stella Kramrisch, The fire myth of Rudra-Śiva plays on the whole gamut of fire, valuing all its potentialities and phases, from conflagration to illumination. The similarities between the two deities is evident in the Satarudriya (Rigveda), where some epithets, such as sasipanjara (of the golden red hue) and tivasjamati (flaming bright) envision Siva as a God of fire. In some of the Vedic hymns Agni is also described as a bull and bull, known as Nandi, is the vehicle of Shiva...
Indra was the supreme deity of the early Vedic religion. He is considered to be the God of thunder and the Lord of the heavnes. He wields lightning as his weapon, slews the dark monsters (clouds) of the skies and releases the water for the welfare of the people on earth. He also sends terror in the hearts of the enemies of His worshippers. He is described as a great warrior who destroyed several cities ruled by evil demons. According to some scholars as the popularity of the early Vedic deities decline and new gods such as Shiva and Vishnu emerged on the scene, some of the early descriptions associated with Indra were subsequently transferred to Shiva. According to the Indologist Koenraad Elst, there are reasons to believe that Shiva of Puranic Hinduism is a continuation of the Vedic Indra. For example, both Shiva and Indra are known for their addiction to Soma. Both are associated with such popular symbols as mountains, rivers, male fertility, fierceness, fearlessness, warfare, transgression of established mores, the Aum sound, and the Supreme Self. Besides in the Rig Veda, the term Shiva is used as an epithet to describe Indra. (R.V 2.20.3, 6.45.17,and 8.93.3)
Even more on the roles of Shiva-Rudra and Ahura Mazda(#) and their relationships with the Mitra-Varuna-Indra deities. See Mithraism: Mithr Kh啾thrapati and his brother Ahur by: Professor Mary Boyce
#Kuiper (IIJ I, 1957) proposes that none less than Ahura Mazda is a development from an earlier dvandva *vouruna-mitra. The basis of Kuiper’s proposal is that the equivalent of Avestan mazda “wisdom” is Vedic medhira, described in Rigveda 8.6.10 as the “(revealed) insight into the cosmic order” that Varuna grants his devotees. In Kuiper’s view, Ahura Mazda is then a compound divinity in which the propitious characteristics of *mitra negate the unfavorable qualities of *vouruna. While Ahura Mazda is uniformly “the mightiest Ahura” (e.g. Yasna 33.11), in the only two occurrences of the term where the word does not refer to Ahura Mazda, the poet uses the expression mazdasca ahurano (Yasna 30.9, 31.4). This phrase, generally understood to mean “the Wise [Mazda] One and the (other) Ahuras”, is in “common opinion” (so Boyce 1984:159) recognized as being archaic and in which the other Ahuras are *mitra and *varouna. Boyce (Mithra the King and Varuna the Master, 2001) sees this supported by the younger Avestan dvandvah expression mithra ahura berezanta “Mithra and the High Lord”, the latter being unambiguously Ahura Berezainti, “High Lord” Apam Napat, the third member of the Ahuric triad (Gray, Foundations, 1929:15), and with whose Indian equivalent (also Apam Napat) Vedic Varuna is closely associated.(Wikipedia http://en.wikipedia.org/wiki/Varuna