The Battle of the Shark and the Octopus Summarization

There was a Fijian god called Takuaka, who was the most famous of the gods that guard the reef. He often turned into a shark so that he could defeat the reef gods. He challenged most of the reef guardians, and won every battle. One day, after meeting an old friend, he found and challenged another guard. But this time, he lost, and he promised that, as long as he lived, that he wouldn't hurt anymore people.