Valakilyas are a group of tiny sages mentioned in Hindu scriptures. The sages were the size of the thumb but were very powerful due to their piety, Brahmacharya and intense penance. Once, Indra and the Valakilyas were on their way to the ashram of Sage Kashyapa to attend a yajna.
Indra, the king of celestial beings, was haughty and arrogant and this behavior often caused problems to the celestial world. On the way to the ashram, Valakilyas had fallen into water collected in a hoof mark left by a passing animal. Indra, who soon reached the spot, mocked at the tiny sages who were in a puddle and sped away.
Sage Kashyapa received Indra but was a worried man because Valakilyas had not yet reached. Indra then jokingly narrated what had happened and asked Sage Kashyapa to not to wait for the tiny sages.
Sage Kashyapa narrated how powerful the Valakilyas were and he also warned Indra that they might be performing a yajna to replace Indra as the king of Devas.
Soon Indra and Sage Kashyapa reached the spot of the yajna and asked the Valakilyas to desist from it.
The sages relented and said that the one to come from the yajna would Pakshindra, king of all birds, and that bird was Garuda.
With the blessing of Valakilyas, Sage Kashyapa became the father of Garuda.
Indra made the mistake of judging the sages by their outward appearance. Symbolically the story explains one should not judge a person by outward appearance.