Sage Agastya lived in his hermitage keeping the asuras (demons) in the forest under his control. However there were two brother-demons, Vatapi and Ilwala, who, whenever they got the opportunity, tried to needle the sage. Agastya, treating them as children, usually let them go free after inflicting some punishment on them for their wrong deeds.
One day Vatapi complained to Ilwala, “This is no life as there is no action around us. The sage foils every attempt that we make to have fun. What shall we do to get rid of him?”
Ilwala replied, “We shall soon go out of practice on how to create trouble if we have to live this sort of life of inaction.”
Vatapi thought for a while and replied, “Come here. I shall quietly tell you of my plan which I have in mind. Do not reveal it to anyone.”
Ilwala heard the proposal and jumped into action. Next day, disguised as a merchant Ilwala went to the hermitage where many sages lived. Ilwala took a ram along with him to present to the sages. When one of the sages came out of his hut followed by others, Ilwala said to him, “I have brought a beautiful ram for you. It is very bright and sprightly. It has curved horns that shine like silver and his eyes glitter in the darkness. You can use this animal for sacrifice and the gods shall be very happy at your gift to them.”
The sages were pleased at the gift and wanted to know what they had to pay for it. The asura replied, “I do not want anything for it. Just allow me the permission to stay here with you.”
The sages were happy to hear this and gave Ilwala a place to stay. They took the ram to the altar to sacrifice it. They killed it and after making the sacrifice, cooked a portion of the meat to offer to the gods as a sacrifice. They then ate a portion of this sacrificial food. After the last morsel had been eaten, Ilwala called out to his brother, “Vatapi, come out, I need you.” At this bits of Vatapi emerged from the stomachs of the sages and on touching the ground the bits joined together to become one whole, Vatapi. In the meantime, the sages, after eating the meat lay dead on the ground as Vatapi had poison inside them which entered their bodies when they had consumed.
The brothers happily returned home. After some time, they again felt the urge to do something to brighten their life. They decided to try the same trick on Sage Agastya. Next day Ilwala, disguised as a merchant, took a ram and presented it to sage Agastya. After eating the ram’s meat, Agastya sat looking smug. Ilwala called out to his brother to come out of the sage’s stomach but this time nothing happened. Sage Agastya began to laugh, “I knew you were up to something. Unlike the sages whom you killed earlier, I have a very strong constitution and that is why I did not die. Now that Vatapi is dead as his meat has been eaten by me, now you will be left alone and will not be able to do much by yourself.”
Ilwala became so angry that he kicked at the sage but the latter stared hard at Ilwala with fire emitted from his eyes. Ilwala was burned to ash.
Peace now came to reign upon the forest.