Ryuboshi

Ryuuboshi is an oarfish fishman and the second son of the royal Neptune family on Fishman Island. He first appeared in Mermaid Cove along with his brothers Fukaboshi and Manboshi, looking for Luffy because of his illegal entry. He has a habit of ending his sentences by singing a part of a musical scale, such as "so-la-si-do" or "mi-re-do." He and his younger brother Manboshi apparently like to dance, as he suggested it to him while Fukaboshi was asking the mermaids about the Straw Hats. After Keimi, Luffy, Usopp, and Chopper escaped, Ryuuboshi explained that they were looking for the Straw Hats for a reason other than their illegal entry, to give them a message from Jinbe.