Longest caecum proportionately for an animal

The animal with the proportionately longest caecum (a pouch at the beginning of the large intestine) is the koala Phascolarctos cinereus. This familiar Australian bear-like marsupial's caecum measures 200 cm in length, and is 10 cm in diameter. By comparison, the koala's own total length is 60–85 cm. In herbivorous mammals such as the koala, the caecum contains bacteria that help to break down the cellulose present in plant material fed upon by these mammals.