Boobo stands as Gamba's best friend and childhood companion, a bond established early in their story. Originally a town mouse, he shares Gamba's starting environment before embarking on a journey. He sports distinctive green fur, making him visually unique. His personality is defined by gluttony and an easygoing, absentminded nature, traits reflected in the origin of his name. A key physical attribute is his sensitive nose, practically employed to locate food during their travels.

Motivated by hunger and threats in their town, Boobo joins Gamba on the initial voyage to the sea. After encountering the injured mouse Chūta and learning of Noroi's tyranny on Yumemishima Island, he commits to aiding the defense effort alongside Gamba. His involvement extends to assisting in recruiting allies at the harbor and sailing to confront the Noroi Clan.

In the 2015 film adaptation *Gamba: Gamba to Nakama-tachi*, Boobo's narrative role is reduced to secondary status. His original functions as Gamba's primary companion and participant in the core journey are largely transferred to a new character, Manpuku.