Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Cows can sleep standing up, but they can only dream lying down.
745
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Alligators can live up to 100 years.
337
When you shave a guinea pig it looks like a little hippo.
19