Hippos are the world’s third largest land mammal, after elephants and white rhinos, weighing up to or over 4,000 pounds and measuring up to 5 feet tall at the shoulder. Despite their large, bulky physique, hippos thrive in semi-aquatic environments, allowing them to move swiftly underwater and on land. Their feet have four-webbed toes, which, combined with their stocky legs, help hippos propel themselves through the water. The Nile hippo’s ears, eyes, and nostrils are located at the top of their heads, allowing them to stay alert and breathe while almost completely submerged underwater.