Coypu is a synonym of nutria.

As nouns the difference between nutria and coypu

is that nutria is the coypu, Myocastor coypus while coypu is a large, crepuscular, semiaquatic rodent (Myocastor coypus) resembling a large rat, having bright orange-yellow incisors, native to South America and introduced to Europe, Asia and North America, valued for its fur in eastern Europe and central Asia and considered a pest elsewhere.