This legend relates to the encounter between Arjuna the Pandava prince and Shiva, and is an important event in the epic Mahabharata.
Arjuna the valiant Pandava prince, during the princes' exile in the jungles, went out to the Himalayas to worship Shiva, to win from him the Paasupataastram, the infallible weapon. His penance bore fruit, when Shiva, in the guise of a hunter (Kiraata) donning a bow appeared before him, picked up a quarrel with him over a wild boar, and challenged him to a combat. This manifestation of Shiva is known as Kiraata Murthy. In the course of this (mock) fight, the hunter stripped Arjuna of all his weapons (and his ego), and the brave prince continued to fight with his bare hands. Shiva then revealed his true self, and blessed him with the Paasupataastram.
Arjuna's encounter with Shiva is celebrated at Tiruvetkalam near Chidambaram - Tamilnadu.
Kiraata Murthy is also revered at Kumbhakonam (Tamilnadu) , where it is believed that an arrow from Shiva's bow pierced the pot containing the celestial nectar amritam, and spilled it into the Mahamagam tank.