Giant river otters are large aquatic mammals native to the rivers and lakes of South America. They can grow up to 6 feet long and weigh between 50 to 100 pounds. These otters have thick, water-repellent fur and webbed feet, making them excellent swimmers. They primarily feed on fish, but they also eat crustaceans and small mammals. These social animals live in family groups, often consisting of 3 to 10 individuals. Giant river otters are known for their playful behavior and vocalizations, which include barks and whistles. They are considered endangered due to habitat loss and hunting for their fur, making conservation efforts essential for their survival.