The Giant Beaver is a mystery rodent, reported from Labrador, New Brunswick, and Nova Scotia. Mishtamishku-shipu (Giant Beaver River), Labrador, 54°40' N, 62°25' W, was named for the animals that were killed there, according to the local Montagnais- Naskapi people.
Not much information is available from the Native American legends, even on size. However, the animal must have been larger than the American beaver (Castor canadensis), which is about 2 feet–2 feet 6 inches long, with a 10-inch tail.
The Giant beaver created much damage with its huge dams. The Indian folk hero Gluskap set out to destroy it but wound up chasing it further west.
- Surviving Giant beaver (Castoroides ohioensis), a large North American beaver that ranged from the Yukon south to Florida and from New York west to Nebraska and apparently died out 10,000 years ago. It was 7 feet 6 inches long and may have weighed 440 pounds. Its cutting teeth were 6 inches long, with strong enamel ridges. The tail was apparently round, not flat.