Mangaia
A girl named Hina-moe-aitu ("Hina-sleeping-with-a-god") liked to bathe in a pool that housed many eels. One day, as Hina was bathing, one of the eels transformed into a young man. Hina took him as her lover. His name was Tuna.
After they had been together for a while, one day Tuna told Hina that there would be a great downpour the next day. He would be washed up onto the threshold of her house in his eel-form. When that happened, Tuna said, Hina must cut off his head and bury it, and then regularly visit the place where the head had been buried.
Hina obeyed Tuna, returning faithfully to watch the place where she had buried his head. After many days, she saw a shoot sprout from the spot. Another shoot appeared, and the two shoots grew into a pair of coconut trees—the first coconut trees known to man.
In Mangaian tradition, the coconut's white flesh is called "Tuna’s brains", and it is said that one can see a face when one looks at the shell of a coconut.
Read more about this topic: Hina (goddess)