Myocastor coypus is a semiaquatic rodent native to South America, also known as the nutria or coypu. It has a distinctive orange-brown fur, webbed feet, and a long tapered tail, making it well adapted to life in the water. The nutria is considered an invasive species in many parts of the world due to its destructive burrowing habits and environmental impact. Synonyms for the Myocastor coypus include the river rat, swamp beaver, and water rat. These names reflect the nutria's aquatic nature and general appearance, and are often used interchangeably. Despite its negative impact on ecosystems, the nutria remains an interesting and unique animal to study.