Wikipedia
In Fijian mythology, Dakuwaqa (Dakuwanga) is a shark- god. He was greatly respected by fishermen because he protected them from any danger at sea and sometimes protected them from evil denizens of the sea.
He was once going inland to conquer Kadavu Island through the river when another goddess challenged him in the form of an octopus. After a great battle, the octopus won (mainly due to her 8 arms which enabled her to hold off the massive attack of Dakuwaqa) forcing Dakuwaqa to promise to never attack Kadavu again. That is how Dakuwaqa became the god and protector of Kadavu. Dakuwaqa can also change shape into anything, but his real form is that of a muscular Fijian man with the upper torso of a shark.
In the book Pacific Irishman, the Anglican priest William Floyd records in Chapter 1, Creation: