The male seahorse carries babies and 'gives birth' to them instead of the female.
7
Cats and dogs can hear ultrasound.
350
There is a sea snail that wears a suit of iron plated armor. It is the only known animal to use iron sulphide as skeletal material.
9
Dire wolves actually existed, living up to 10,000 years ago before going extinct.
10
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The elephant brain weighs about 6,000g.
274