This episode is from valmiki ramayanam the 18^th chapter:

This has been explained by sage agasthiyar to rama that…

So goes the saying if one feeds the crow it goes to our ancestors but then how did it get this blessing is the story here…

The king maruththan of usirabeejan conducted a yaga and had invited Indiran, and many other devaas it was guru’s brother samvarthar conducted the yaga in the lead.

In a while ravana along with all his friends entered the yagasala and he was a powerful man with many blessing from gods, which squirmed the devaas no end.

To escape from him they turned themselves as birds and animals in his presence,

Indira became the peacock, yama dharma became the crow, khubera and varunan became

Chameleon and swan..

The king maruththan was fearless so wanted to wage a war against ravana, samvarthar advised that the yaga will be disrupted so no war now. None came forward to fight him so ravana announced it is taken for granted that he is the winner and the king maruththan has lost the war. He went away from the yagasala along with his friends.

The devaas were relieved and changed into their original form, but to show their gratitude towards the birds and animals they blessed them, the peacock got its beautiful wings which when spread is a beauty to behold, he also bestowed that they need not fear the snakes but would feed on them.

The yama dharma blessed the crow with good health, and no disease will affect it much, and none will eat you or hunt you, [yes I know u r reminded of vivek’s joke as kaka biryani] there are always exceptions in kaliyuga, and any one who gives u some food will be serving the dead in my land..

Khubara blessed the chameleon to change its color and escape in the environment at the sight of danger. Lord varuna blessed the swan with intelligence and pure white color.

These information are from bhakthi specials brought to you by sunkan