Chimney

Chimney (チムニー, Chimunī) is the hyperactive granddaughter of Sea Train conductor Kokoro, and owner of the rabbit, Gonbe (which thinks it's a cat).

She is 1/4 Mermaid and 3/4 human. Kokoro married a human and together they had a 1/2 Mermaid son who then married another human. Although she retains none of her grandmothers heritage she is a extremely good swimmer due to being descended from a mermaid.

She takes a liking to the Straw Hat Pirates instantly when the crew meets her outside of Water 7. She also tends to notice things that others cannot, such as when she spotted Luffy wedged between two buildings (which is where he landed after Rob Lucci knocked him out of Galley-La Company Headquarters).

She, along with Gonbe, later sneak aboard the prototype Sea Train, Rocketman, and accompany the Straw Hats, Franky Family, and Galley-La foremen to Enies Lobby and later follows Rob Lucci, Spandam and Nico Robin and discovers the entrance they took which she later shows Luffy, Rob Lucci reveals that he knew she was following them but chose not to do anything because he wasn't ordered to.

Currently, she is in Water 7.