The Bodhisatta was once a rat. He lived in the forest and was the leader of a big group of rats. One time a forest fire swept through the forest and a jackal did not have time to flee, so he pressed his head against a tree and stood still as the flames approached. The fire didn’t kill or injure him, it just singed off all his hair, except for a tuft on the crown of his head, which had been covered by the tree.
As he drank water from a pond one time, the jackal noticed the hair on his head in his reflection and devised a scheme to eat the rats by staying near their cave and pretending to be holy. When the Bodhisatta saw the jackal, he assumed he was holy and went to speak with him. The jackal explained he was a worshiper of the Fire-God and he had come here to guard the rats, which he would do by counting them each time they left the cave in the morning and returned in the evening, so the Bodhisatta would know if any were missing.
The Bodhisatta believed him and was pleased to accept his help. Each time the jackal counted the rats, he ate the last one in line. Eventually the rats noticed their group had grown smaller and they told the Bodhisatta. Hearing this news, he suspected it was the jackal, so the next time they passed him, the Bodhisatta walked at the end of the line. When the jackal began to strike, the Bodhisatta turned around to rebuke him and then sprang at the jackal’s throat, biting hard into his windpipe and killing him. The other rats came back and devoured the entire body.
In the Lifetime of the Buddha
The jackal was an earlier birth of one of the Buddha’s disciples who had been exposed as a hypocrite. The Buddha told this story so the other disciples knew he had been the same way in the past.