The river otter is a playful and agile mammal found in North America, often inhabiting rivers, lakes, and coastal areas. They have a streamlined body, webbed feet, and a thick fur coat that keeps them warm in cold water. River otters are excellent swimmers, using their long tails to propel themselves through the water. These animals are social and often live in family groups. They primarily feed on fish, crustaceans, and small mammals, using their sharp teeth to catch and consume prey. River otters are known for their playful behavior, often sliding down mud or snowbanks and engaging in games with each other.