The Jataka, Volume I, tr. by Robert Chalmers, , at sacred-texts.com
"Fear’st thou the wind."--This story was told by the Master while at Jetavana, about a Brother who lived in a perpetual state of nervous alarm. We learn that he came of a good family in Sāvatthi, and was led to give up the world by hearing the Truth preached, and that he was always in fear of his life
both by night and by day. The sough of the wind, the rustle of a fan, or the cry of bird or beast would inspire him with such abject terror that he would shriek and dash away. He never reflected that death was sure to come upon him; though, had he practised meditation on the certainty of death, he would not have feared it.  For only they that do not so meditate fear death. Now his constant fear of dying became known to the Brethren, and one day they met in the Hall of Truth and fell to discussing his fearfulness and the propriety of every Brother's taking death as a theme for meditation. Entering the Hall, the Master asked, and was told, what they were discussing. So he sent for that Brother and asked him whether it was true he lived in fear of death. The Brother confessed that he did. "Be not angry, Brethren," said the Master, "with this Brother. The fear of death that fills his breast, now was no less strong in bygone times." So saying he told this story of the past.
Once on a time when Brahmadatta was reigning in Benares, the Bodhisatta was a Tree-Sprite near the Himalayas. And in those days the king put his state elephant in the elephant-trainers' hands to be broken in to stand firm. And they tied the elephant up fast to a post, and with goads in their hands set about training the animal. Unable to bear the pain whilst he was being made to do their bidding, the elephant broke the post down, put the trainers to flight, and made off to the Himalayas. And the men, being unable to catch it, had to come back empty-handed. The elephant lived in the Himalayas in constant fear of death. A breath of wind sufficed to fill him with fear and to start him off at full speed, shaking his trunk to and fro. And it was with him as though he was still tied to the post to be trained. All happiness of mind and body gone, he wandered up and down in constant dread. Seeing this, the Tree-Sprite stood in the fork of his tree and uttered this stanza:--
 Such were the Tree-Sprite's cheering words. And the elephant thenceforth feared no more.
His lesson ended, the Master taught the Four Truths (at the close whereof the Brother entered the Paths), and identified the Birth by saying, "This Brother was the elephant of those days and I the Tree-Sprite."