A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The CIA once spent $20 million on a cat equipped with gear to spy on the Soviets, but it was hit by a taxi.
328
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
If a vampire bat goes 2 days without drinking blood, they can die. However, well fed female bats will puke up blood and share it with other bats that they like in exchange for grooming.
13
The Hercules beetle, despite weighing only 100 grams, can lift 8 kilograms, making it one of the proportionally strongest animals in the world.
8
Bats sleep 18-20 hours per day.
5
Cats are one of the only animals to domesticate themselves and approach humans on their own terms.
20