Neptune

King Neptune (ネプチューン王) is a coelacanth merman and the king of the Ryugu Kingdom on Fishman Island. He is the father of Fukaboshi, Ryuboshi, Manboshi, and Shirahoshi.

Appearance
Neptune is a large, muscular, and hairy coelacanth merman. He has long curly hair and a curly beard and a darkened nose. As king, he wears a crown that resembles a tulip and carries a trident. He has matching tattoos on both arms.

Personality
He appears to be very protective of his family, as he had his sons form an army solely to track down Vander Decken IX so that the pirate would stop harassing his daughter. He also seems to be very blunt, as he simply invited the "Straw Hat humans" to the Ryugu Palace, instead of being more cordial. He appears to be easy-going and carefree as he was scolded by his ministers for leaving the castle on a whim on more than one occasion.

Relationships
He has a beloved whale named Hoe.

Abilities and Powers
As king, he has royal authority over the entire Ryugu Kingdom. Whether he has any fighting ability is unknown. However, his presence outside the palace is enough to cause a commotion with the inhabitants referring him as "You-Know-Who".

While he is the king of Fishman Island, he has had to rely on the protection of two of the Yonkou: Whitebeard until his death and then Charlotte Linlin (Big Mam) afterwards. He didn't have to pay collateral to Whitebeard, but he does have to pay a monthly fee of sweet candy to Big Mam.

He was seen carrying a trident. He is presumably efficient at using it.

History
He was so angered by Vander Decken IX pestering his daughter through letters, packages, and ultimately marriage proposals, that he had his three sons form an army called the Neptune Army to capture him.

When Megalo tells him about being freed by the Straw Hat Pirates, he looks forward to meeting them. When he learns that Straw Hat Luffy is in Pappug's mansion, he personally travels there to meet him. After making contact with Luffy, King Neptune invites him and his crew to his palace.

As Neptune and Luffy's group travel to the palace, the king complements the Straw Hats on freeing Megalo from the Kraken. Neptune also informs Luffy that Zoro is found and brought to the palace. When Nami inquires about how Fishman Island receives light, Neptune tells her about Sunlight Tree Eve. When they finally arrive at the palace, Neptune gets scolded by his ministers for leaving the castle by himself. They also inform him of a message from Fukaboshi.

Trivia

 * His name comes from Neptune, the Roman god of the sea.
 * His appearance is similar to that of Triton from Disney's "The Little Mermaid".
 * He is a coelacanth merman, the signifance of this being that the Indonesian species is refered to locally as "raja laut", meaning "King of the Sea".