Tangaroa is the father of all the sea creatures, including mermaids, from whence came humanity. The tides are his breaths, and he changes into a green lizard as a portent of good weather. Sailors keep a piece of brain coral in their ship; it is an important talisman to protect them while on the sea.
Alternatively, Tangaroa is the primevil spirit that existed before anything else. Atea and Atanua came from him. He is also the father of Losi in Samoan mythology.
In Hawaii, Kanaloa is a creator god of magic and is associated with the octopus, and is also the king of the underworld.
With Hina-Tu-A-Uta, he is the father of Oro (Tahiti).
Alternative: (Tangaroa is his Maori name), Tanaoa (Marquesas Islands), Ta'aroa, Tangaloa, Kanaloa (Hawaii)