Coypu is a semi-aquatic rodent that is commonly found in North and South America. Although the word coypu is widely used to refer to this animal, there are several other synonyms that can also be used to describe it. One of the most common synonyms for coypu is nutria, which is more commonly used in North America. Other synonyms for coypu include swamp beaver, river rat, and water rat. Despite the differences in terminology, these synonyms all refer to the same animal, which is known for its webbed feet, large front teeth, and distinctive brown fur.