Ryugu

The Ryugu is a ship from Ryugu Kingdom.

Appearance
It is a giant oarfish with a carriage built around its body in order to transport people more easily. The carriage has several oars sticking out of it.

History
While half of the Straw Hat Pirates were enjoying Mermaid Cove, Fukaboshi and his brothers arrived on the Ryugu. Sanji suddenly had a massive nosebleed. Luffy was worried and asked for a donor. When they ignored him, Keimi stole the Ryugu from them and she along with the Straw Hats left in order to find a blood donor for Sanji.

Trivia

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