The nutria or coypu is a large ratlike semi-aquatic rodent from South America. It is also known as the river rat, in some languages as the ‘beaver rat’. The coypu does resemble a beaver but with a rat tail.
Nutria or coypu (Myocastor coypus), Budapest Zoo.
Nutrias are herbivorous. Nutria fur was considered valuable at one point and people have even farmed them for their fur in many parts of the world.
Also nutria meat is edible thus farmed or hunted coypu can be used as food. While not everyone is enthusiastic about eating something that is basically a giant rat, apparently eating nutria meat is not uncommon even in North America.
In several places farmed coypu were released into the wild and established themselves as a breeding feral population, quickly becoming pests.
Further Readings:
Coypu videos, photos and facts – Myocastor coypus on ARKive.
Nutria, Coypu — eattheweeds.com.
Nutria farming had short lifespan — Simcoe Reformer.