Theyyam (Theyyattam or Thira is a popular Hindu ritual form of worship of North Malabar in Kerala, India, predominant in the Kolathunadu area (consisting of present-day Kasargod, Kannur Districts, Mananthavady Taluk of Wayanad and Vadakara and Koyilandy Taluks of Kozhikode of Kerala. As a living cult with several thousand-year-old traditions, rituals and customs, it embraces almost all the castes and classes of the Hindu religion in this region. The performers of Theyyam belong to the lower class community, and have an important position in Theyyam. This is unique, since only in Kerala, do both the upper-caste Brahmins and lower-caste tribals share an important position in a major form of worship. The term Theyyam is a corrupt form of Devam or God. People of these districts consider Theyyam itself as a God and they seek blessings from this Theyyam. A similar custom is followed in the Tulu Nadu region of neighbouring Karnataka known as Bhuta Kola
History
According to the legendary Keralolpathi, Parasurama sanctioned festivals like Kaliyattam, Puravela and Daivattam or Theyyattam to the people of the North Malabar region. He also assigned the responsibility of performing the Theyyam dance to the indigenous tribal communities like Malayar, Panan, Vannan and Velan. "There can be no doubt", say Bridget and Raymond Alchin, "that a very large part of this modern folk religion is extremely ancient and contains traits which originated during the earliest periods of Neolithic, Chalcolithic settlement and expression".
Classification of Sub Cults
It can be said that all the prominent characteristics of primitive, tribal, religious worship had widened the stream of Theyyam cult, where "even the followers of Islam are associated with the cult in its functional aspect" and made it a deep-rooted folk religion of millions. For instance, the cult of Bhagawathi, the Mother Goddesses had and still has an important place in Theyyam. Besides this, the practices like spirit-worship, ancestor-worship, hero-worship, masathi-worship, tree-worship, animal worship, serpent-worship, the worship of the Goddesses of disease and the worship of Graamadevataa (Village-Deity) are included in the main stream of the Theyyam cult. Along with these Gods and Goddesses there exist innumerable folk Gods and Goddesses. Most of these Goddesses are known as Bhagavathy (the Mother-Goddess that is the Divine and United form of the three principal Goddesses namely, Brahmani (Saraswati), Vaishnavi (Lakshmi), and Shivani (Durga)).
Different branches of mainstream Hindu religion such as Shaktism, Vaishnavism and Shaivism now dominate the cult of Theyyam. However, the forms of propitiation and other rituals are continuations of a very ancient tradition. In several cult-centres, blood offering is seen, despite being forbidden in sattvic Hinduism, Jainism and Buddhism. In such centres, separate places outside the precincts of the shrine are selected for blood offering and for the preparation of the traditional Kalam known as Vatakkanvathil. The Theyyam deities propitiated through cock-sacrifice will not enter such shrines. This religious cockfight over blood sacrifice, which does also include the cockfight as a blood sacrifice, is a prime example of "cultural synthesis of 'little' and 'great' cultures".
On account of the supposedly late revival of the Vaishnavism movement in Kerala, it does not have a deep impact on the Theyyam cult. Only a few deities are available under this category. Two major Theyyam deities of Vaishnavism are Vishnumoorthi and Daivathar. Vaishnavism was very popular in the Tuluva region in the 13th century when it came under the rule of Vishnuvardhana of the Hoysala dynasty. He was a great champion of Vaishnavism. Most probably he was initially deified as Vishnumoorthi and incorporated into the Bhoota cult of the Tuluvas and then further incorporated as a prominent folk deity into the Theyyam cult as well. To some, the legend of Vishnumoorthi is symbolizes the God's migration from Tulu Nadu to Kolathunadu.
All other categories of Theyyam deities can be classified under Shaivism or Shaktism. Even spirits, ancestors, heroes, and animals are deified and included in those categories. Briefly, Theyyam provides a good example for the religious evolution of, and the subsequent different stages in modern Hinduism, with the overall understanding that within Hindu sycretisms lay propitiation as ancient practices and rituals of ancient worship intended for the blessings of the supernatural not unlike, "in Indus Valley and other ancient civilizations, mother goddess had been invoked for fertility and prosperity".
For more information: https://en.wikipedia.org/wiki/Theyyam