Bhairava Ashtami, also known as Bhairavashtami, Bhairava Jayanti, Kala-Bhairava Ashtami and Kala-Bhairava Jayanti is aHindu holy day commemorating the birthday of Bhairava (lit. “terrible”), a fearsome and wrathful manifestation of the god Shiva. It falls on the eighth lunar day (ashtami) in the fortnight of the waning moon (Krishna paksha) in the Hindu month of Kartik (per the South Indian Amavasyant calendar, every month ends with a new moon) or Margashirsha (per the North Indian Purnimant calendar, every month ends with a full moon). By both schemes, Bhairava Ashtami falls on the same day in November–December. The nameKalashtami is sometimes used to refer to this day, but might also refer to any ashtami in Krishna paksha, all of which are sacred days of Bhairava, who is also called also Dandapani (as holds a rod or Danda to punish sinners) and he rides a dog he is also known as Swaswa meaning “whose horse is a dog”.
Bhairava is an manifestation of Shiva’s wrath. According to the legend narrated on the occasion, the Trimurti gods, Brahma, Vishnu and Shiva were talking in a serious mood as to who was superior of them all. In the heated debate, Shiva felt slighted by remarks made by Brahma and instructed his ganor Bhairava to cut off one of Brahma’s five heads. Bhairava followed Shiva’s orders and one head of Brahma was cut off and thus he became four headed. Instilled with fear, all others prayed to Shiva and Bhairava.
Another slightly modified version is that when Brahma insulted Shiva, Bhairava (Kala-Bhairava) appeared from the angry Shiva’s forehead and severed Brahma’s head, leaving him with only four heads. The head of Brahma stuck to Bhairava’s left palm due to the sin of killing Brahma, the most learned Brahmin – Brahmahatya or Brahminicide. To expiate the sin of brahmahatya, Bhairava had to perform the vow of a Kapali: wandering the world as a naked beggar with the skull of the slain as his begging bowl. Bhairava’s sin is finally expiated when he reaches the holy city of Varanasi, where a temple dedicated to him still exists.