Carue, also spelled "Karoo", is Vivi's pet spot-billed duck, a fast-footed riding bird (one of the fastest modes of transportation available in Arabasta). His role during Vivi's time with the Straw Hat Pirates is mostly that of comic relief, although he does relay valuable information to Chopper from time to time, helps Luffy and Usopp to defeat the Baroque Works agents in Little Garden and saves Vivi from Mr. 2 Bon Kurei in Arabasta. He is the center of several jokes in the Arabasta arc, at one point being used as bait for fishing by Luffy and Usopp to Vivi's anger and chagrin, and he is mistaken for an ostrich by Sanji. He is the leader of the Super Spot-Billed Duck Squad in Arabasta. Source: One Piece Wikia