Gwin is a horned marten of Dustfinger's. Dustfinger found him in the Inkworld. The only person that Gwin likes better than Dustfinger is Farid. Gwin is usually kept inside of Dustfinger's backpack. Gwin first appears when Dustfinger shows him to Meggie in the camper van. Gwin was supposed to be the death of Dustfinger. Fenoglio wrote the story of Inkheart so that Capricorn's men would chase be chasing after Gwin (trying to kill him) and Dustfinger tried to save him, but ends up dying. Gwin nearly got Dustfinger killed at the Spelt-Mill. Although described as a marten in the stories, he appears as a ferret in the movies