The most fundamental of Hindu deities, is the Trinity of Brahma, Vishnu and Shiva - popular deities include Ganesha, Krishna, Hanuman and goddesses like Lakshmi, Durga,Saraswati.
This legend relates to the story of Shiva's protecting Markandeya from the clutches of death.
Mrikandu Munivar worshipped Shiva and sought from him the boon of begetting a son. He was given the choice between a gifted son with a short lived tenure on earth or a dunce with a long life. Mrikandu Munivar chose the former, and was blessed with Markandeya, an exemplary son, destined to die at the age of 16.
Markandeya grew up to be a great devotee of Shiva. On the day of his destined death Markandeya continued to worship a Shivalingam. The messengers of Yama, the God of death were unable to take away the lad's life, given his devotion to Shiva and his being engaged in the act of worship then. Yama himself came in person to take his life away and sprung his noose around the young sage's neck. The noose landed around the Shivalingam, and out of it, Shiva emerged in all his fury, and kicked Yama and killed Death itself. He then revived him, under the condition that the devout youth would live for ever.
This legend of Shiva killing death itself, is frozen in metal and held in worship at Tirukkadavur. Tirukkadavur is the shrine where thousands throng to celebrate shashti abda poorthi (60th birthdays), with the belief that the blessings of the deity enshrined would prolong their lives. Tirukkadavur is one of the 8 Veeratta temples celebrating Shiva as the destroyer of evil forces.