Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.
4
Lurch, a Watusi bull, had the largest horns in the world.
32
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
Rattlesnake mating sessions have been known to last more than 22 hours.
232
The elephant brain weighs about 6,000g.
274