Down in the Marish in the far east of the Shire, the land of the Hobbits drew near the River Brandywine and the edge of the world beyond. The Shire-folk in this region were more cautious than their fellow Hobbits who lived farther from the borders, and so they sought protection from the dangers beyond the River.
For Farmer Maggot of Bamfurlong, that protection came in the form of three large, wolf-like dogs, one of which he gave the name 'Fang' (the other two were named 'Grip' and 'Wolf'). These ferocious but well-trained animals lived at his farm at the time of the War of the Ring, but he had evidently kept other dogs before these. Frodo had frightening memories of Maggot's dogs going back some thirty years, but the dogs that had threatened him three decades earlier could hardly have been Fang, Grip or Wolf.