It may well be that a Muslim legend told by Rudyard’s father was the inspiration for the story: “It was on his back that the body of Shah Ali Shah was laid after his death, and he was sent into the wilderness till the Angel Gabriel met him and, taking the rope, led him no man knew whither. Before that ghostly funeral the camel resembled a horse, but the Angel Gabriel gave him a hump like the mountains into which he disappeared”
However in this version the hump(h) is not a reward, but rather a stimulus to share in the daily round and common task along with the other animals. A point which is made very clear by the song that follows the story.
Again I have included Kipling’s charming descriptions of his pictures.