Where do the aboriginals believe the kangaroo is from?

Aboriginal Dreaming stories tell how and why different animals were created. One such story tells of a man who, for various reasons, had a fight with another tribe member. This other man hurled a spear at the kangaroo man who turned, receiving the spear in the base of his spine. From then on he was only able to hop, with the spear protrudung, until he finally turned into a kangaroo.