Gonbe is Chimne's pet cat even though he is actually a rabbit.
Appearance
Gonbe thinks he is a cat even though it clearly has a rabbit's body, such as long ears and tail. Most of his body is covered in light blue fur with a creamy face and front. Like Chimney, Gonbe always looks with a big smile on his face. Two years later, Gonbe has become a little bigger and looks more like a normal rabbit.
Personality
Gonbe has never been seen far from Chimney. He always goes wherever his master is and imitates every action. He is rarely seen without a big smile. He is sure that he is a cat, even making a sound like a cat ("Him" for cat sounds in Japan).
History
Water 7
After meeting the Straw Hat Crew, Chimneydan Gonbe with Kokoro's grandmother went to Water 7 after Aqua Laguna arrived. They reappear when Franky goes to Bluen bar to refill the cola.
Enies Lobby
Secretly Chimney and Gonbe sneak up Rocketman to Enies Lobby. There, they both followed Rob Lucci, Spandam and Nico Robin through a secret road. They then bring Luffa through the road and watch the straw hat destroy the door with its strength. When Luffy fights Lucci, Chimney, Gonbe, Kokoro, Nami and Chopper walk through a secret tunnel. When Lucci flooded the tunnel, Kokoro turned into a mermaid and saved the group. There, Kokoro, Chimney and Gonbe watched over Chopper who couldn't move while the rest of the straw hat crew were busy fighting the Navy. After Luffy defeated Lucci, everyone plunged into the sea and fled with the Going Merry.
After sailing away from Enies Lobby, the group meets Iceburg and other Galley-La workers. After the Going Merry was damaged, they also attended the funeral of a Viking-style ship.
Post Enies Lobby
Back at Water 7, Chimney, Gonbe and Kokoro's grandmother lived with a straw hat crew at the Galley-La Company headquarters. They then attended a large party in the city center. After Franky joins the straw hat crew and goes sailing, Chimney and Gonbe are seen crying too.
Where are they now?
Chimney, Gonbe and Kokoro's grandmother are seen at the sea train station, rejoicing with Yokozuna since he no longer fought the train.
From Ship Decks Around the World
Gonbe is seen still with Chimney, who has grown up and is the guard of the sea train station.
Source : WIKIA ONE PIECE