There's a young hippo and a 130+ year old tortoise in a Kenyan wildlife preserve who are best friends and they even sleep and play together.
40
Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.
4
Some older/less efficient worker termites will develop 'backpacks' of toxic chemicals that explode when the termite is threatened. They are essentially used as suicide bombers when the colony is being attacked.
8
Dolphins have names for one another.
18
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
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
A scorpion can hold its breath for up to 6 days.
19
The elephant brain weighs about 6,000g.
274