The Bodhisatta was once a tree fairy living in a cotton tree. A giant garuda grabbed a giant naga out of the ocean by its tail and flew away. The naga tried to free itself by grabbing a banyan tree with its hood, but the two creatures were so strong that the banyan just came out of the ground. The garuda laid the naga, along with the banyan tree it had grabbed, on the cotton tree, ripped it open, and ate its fat. Then the garuda threw the rest of the carcass into the sea. The Bodhisatta thought nothing of this.
Later, a bird that had been in the banyan tree flew out and took a perch high up in the cotton tree and the Bodhisatta shook with fear. The garuda noticed the tree trembling and asked the Bodhisatta why he was afraid of a tiny bird but not a giant, fierce garuda. The Bodhisatta explained that banyan trees are parasitic and if the bird pooped a banyan seed onto the cotton tree, it would eventually overgrow and kill it, leaving the Bodhisatta homeless. The garuda replied that fear is justified when a danger is real and he shooed the bird away.
In the Lifetime of the Buddha
Five hundred friends had heard the Buddha discuss dharma and they renounced the world together to become his disciples. One night, thoughts of desire filled their heads and the Buddha knew about it, so he called an assembly and explained that distrust is proper when you fear something bad can happen. Then he told them this story as an example of how sin can entangle a man the way a banyan entangles its host tree. When the Buddha was finished, all five hundred became arahants.
The garuda was an earlier birth of Sariputta, one of the Buddha’s top disciples.