Legend of Ernakulathappan Temple

Devala was a Rishis disciple serving his Guru in his ashram on the slopes of the Himalayas. One day the boy while collecting material for rituals came across a serpent. Out of fear he killed, it. The Rishi who came to know about this became angry and cursed the boy. As a result, the boys face turned into a serpents-hood. On account of this he came to be known as Nagarshi.

The boy repented and, prayed to the Rishi to restore his original face. The Rishi said this would be possible only if he propitiated Lord Siva. So Nagarshi set out on his pilgrimage to various places of worship all over the country until he came across a Sivalinga at Bahularanyam given to him with a warning that whenever this linga gets stuck, that moment he would be redeemed from his curse. Nagarshi went to a jungle close to a tank and the sea.

Seeing his strange appearance, people tormented him. He hid under a bush. The next while leaving the place, the linga got stuck to the ground and he was relieved of his curse. He decided to take a bath in the tank, while doing so, he disappeared in the lake. Since Nagarshi disappeared in the tank it came to be known as Rishinagakulam which was later corrupted to Ernakulam, kulam meaning tank in Malayalam.