In Cook Islands mythology (Aitutaki), Nganaoa is a hero in the story of Rata's canoe who killed three sea-monsters: a gigantic clam, a huge octopus, a finally a great whale in the stomach of which he found his father, Tairitokerau, and his mother VÄiaroa alive (Gill 1876:147).
References
Nganaoa Wikipedia(Text) CC BY-SA