The giant river otter is a large aquatic mammal native to the rivers and lakes of South America. It can grow up to 6 feet long and weighs between 50 to 100 pounds. These otters have a sleek, streamlined body, webbed feet, and a thick fur coat that helps keep them warm in cold water. Giant river otters are social animals, often living in family groups of up to 20 individuals. They are excellent swimmers and primarily feed on fish, crustaceans, and small mammals. Their vocalizations, including barks and growls, help them communicate with each other while hunting or playing.