It is said that once, about 10 kilometers up the river Pampa from Aranmulla, the head of the Katoor Mana, a Nambudiri family, had a bath in the river. He said his prayers and waited to feed a poor man to complete his ritual. He waited for long but nobody came. Tired of waiting, the Brahmin closed his eyes and began to pray to Lord Krishna. As soon he opened his eyes, he saw a small boy in tatters before him. The devout Brahmin gave a bath to the boy, a set of clothes and a sumptuous meal.
To the surprise of the Brahmin. the boy vanished as soon as he finished his meal. He looked for the boy and spotted him near Aranmulla Temple. But, the boy disappeared again.
The Brahmin came to the conclusion that he was no ordinary boy and was God himself. From then on the Brahmin brought food to Aranmulla Temple every year during Onam.