The Bodhisatta was once a lion. One day he met a jackal in the forest, and being unable to escape, the jackal threw himself at the Bodhisatta’s feet and said he would be his servant if he spared his life. The Bodhisatta accepted the offer. Every day he brought meat back to his home and the jackal ate the leftovers.
The jackal grew large with this arrangement and got arrogant, wanting to kill an elephant by himself. The Bodhisatta replied that no jackal could kill an elephant because they were too small, but the jackal ignored his advice and went out to hunt. When he saw an elephant walking below him, the jackal dove toward it and landed at its feet. The elephant stomped his head, smashing his skull to pieces. The Bodhisatta commented that the jackal died due to pride and everyone should stick to their proper duties.
In the Lifetime of the Buddha
The jackal was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis. He left the Buddha’s sangha with many disciples to set up his own order and declared that he too was a Buddha. The real Buddha sent two of his top disciples, Sariputta and Moggallana, to preach to those wayward disciples; and while Devadatta was asleep most of them chose to return to the Buddha’s fold. This so angered Kokalika, a disciple of the Buddha who became one of Devadatta’s most devoted followers, that he kicked Devadatta in the chest and caused him to spit up blood.
The Buddha told this story to let his disciples know this was not the first time Devadatta had imitated him and suffered for it.