The following is from a work-in-progress called The Mahabharata: a Book Report, in which I'm slowly reading through the Hindu epic poem The Mahabharata, and writing a book report on what I read.
This is a continuation of the story of Kadru and Vinata--who had the snakes and birds for children. Upon encountering the divine horse Uccaisravas, the two women made a wager over the color of the horse. Vinata bet that it was white; Kadru bet that it had a black tail. The loser of the bet would be a slave to the winner. Kadru, being the more devious of the two, tried to persuade her snake sons to pretend to be the horse's tail. When they refused, she cursed them to die in King Janamejaya's snake sacrifice. Ultimately, Kadru won the bet, and Vinata became her slave.
Meanwhile, Vinata's second egg hatched, and out came the divine bird Garuda, destined to free his mother from her curse. But before he could to this, he too was a slave to the whims of Kadru. Once, Kadru commanded Garuda to carry her snake sons to the “Island of the Snakes” for a kind of vacation. En route, Garuda flew very close to the sun, in an effort to kill his snake cousins. But the snakes appealed to the god Indra, who saved them with cooling rain.
On the Island of the Snakes, the enslaved Vinata and her bird-son asked the snakes how they might become free from slavery. They responded, “Bring us the amrta, the nectar of immortality!” So Garuda set off on a journey to find the amrta, which would break his mother’s curse. Garuda had a big appetite and wasn’t shy about eating people and large animals. He ate thousands of the Nisada people, sparing only the Brahmins, the top social caste.
Then Garuda met his father, the seer Kasyapa, who told his bird-son that, the next time he became really hungry, he should eat these two seers who cursed each other to become a giant turtle and a giant elephant. After saving some Brahmins, Garuda ate the giant turtle and elephant. Word reached the gods that this mighty bird-boy was on a mission to steal the amrta. Indra told the gods, “Protect the nectar of immortality!”
At this point, the seer Saunaka again interrupts the storyteller Ugrasravas, asking him how a bird-boy could possibly be powerful enough to challenge the gods. Basically, Ugrasravas explains, Garuda the bird-boy was a new and improved incarnation of the god Indra. Then he continues his story.
So Garuda the mighty bird-boy/new and improved Indra single-handedly went to war with the gods. This dude had guts, and way more power than anyone expected. He beat back the gods and captured the precious amrta, the nectar of immortality!
At this point, something kind of amazing happened. Garuda made a truce with both Vishnu and Indra, and they exchanged “boons,” or special gifts (the opposite of curses). Gaurda agreed to be the trusty mount of Vishnu, and he promised Indra that he would return the amrta after his mother was freed from her curse. Thus, the mighty Garuda freed his mother from her curse.