Ryugu

The Ryugu are ships from Ryugu Kingdom. They are oarfish with a carriage built around their bodies in order to transport people more easily. The carriage has several oars sticking out of it. Fukaboshi and his brothers arrived with one at Mermaid Cove and later Keimi stole that from them in order to find a blood doner for Sanji.

Trivia

 * The writing on the carriage says 竜宮城 (Ryūgū-jō), meaning Ryugu Palace.