Tubgutt was a male shrew of Guosssom and he had an enormous appetite similar to 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. Tubgutt tried to rebel against Log-a-Log in the Great Inland Lake, but failed.
Later Mara saved him from The Deepcoiler and Tubgutt became a friend of Mara and Pikkle. He accompanied them to the island in the center of the lake. Tubgutt's sister was married to a shrew called Forbun.