The evolution of Mannarasala as the supreme place of worship of the serpent Gods is associated with Parasurama, the son of Jamadagini and a descendant of Bhrigu. When Parasurama decided to seek atonement from the sin of killing the Kshatriyas, he approached the holy Rishis. They suggested that he should make a gift of land of his own to the Brahmins. Parasurama propitiated Varuna Deva to get some land for himself. Nagaraja granted his request with great pleasure. Ferocious serpents arrived at the spot at once to spread the flaming Kalakuda poison. Because of the percolation of poison, the land of Kerala was desalinated, to become habitable with greenery. Parasurama then requested the Lord to bless the land forever with his eternal presence, and that was also accepted by the kindly-disposed Nagaraja.