Hippos are surprisingly fast runners, reaching up to 50kp/h over short distances — quicker than the fastest human. They usually bear single calves that are born underwater, weighing up to 50kg. A ...

Due to hippos' dense bone structure and heavy bodies, hippos sink in water, according to BBC Earth. This makes it hard for the animals to swim. Despite this, hippos spend " up to 16 hours per day ...

Pygmy hippo Mars didn’t listen to the zoo caretaker when play time in the pool was over, so his mom, Posie, had to step in.

Common hippos can weigh anywhere from 3,000 to 4,000 pounds. Pygmy hippos, on the other hand, weigh much less, about 400 to 600 pounds.

This newborn baby hippo is swimming straight into our hearts. Born Tuesday at the San Diego Zoo, the new calf can be seen learning to swim with his mom in a new video posted to the zoo's YouTube ...

This newborn baby hippo is swimming straight into our hearts. Born Tuesday at the San Diego Zoo, the new calf can be seen learning to swim with his mom in a new video posted to the zoo's YouTube ...

Obi's name means "heart" in Igbo, a local Nigerian language. He weighed 11 pounds when he was born, but is already up to 28 pounds. Pygmy hippos can grow to eventually be 350-600 pounds.

Despite their large size, hippos eat only 88 pounds of food per night, according to the San Diego Zoo. While this may seem like a lot for humans, this is around 1 to 1.5% of a hippo's body weight.