Tubgutt was a male shrew member of the Guosssom; he had an enormous appetite that was comparable to that of a hare. He disliked Mara and Pikkle (who called him 'Tubbyguts') at first and Tubgutt even challenged Pikkle to a pudding eating contest, losing to the hare. He had a sister.
Tubgutt tried to rebel against his leader, Log-a-Log, in the Great Inland Lake, but failed. Later, Mara saved him from The Deepcoiler and Tubgutt befriended her and Pikkle. He accompanied them to the island in the center of the lake.