The Bodhisatta was once a woodpecker living in a grove of acacia trees. A woodpecker friend who lived amidst fruit and silk-cotton trees came to visit and the Bodhisatta pecked out insects to give him. The friend figured that if the Bodhisatta could get food from acacia wood, then so could he since they were both woodpeckers. The Bodhisatta warned him that they were not of the same tribe and this hardwood was dangerous for him. But the servant did not listen and on his first peck his beak snapped off, his eyes fell out of his head, his head split, and he fell down to the ground dead.
In the Lifetime of the Buddha
The woodpecker friend was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis. He had left the Buddha’s brotherhood and tried to start his own, but failed. The Buddha told this story so people knew that Devadatta had also tried to imitate him in the past and had come to ruin because of it.