Lions are unique among cats in that the male can be easily distinguished from the female (lioness) because he possesses a mane of hair.

As in most cats, the eyes are adapted for seeing at night when they do a lot of hunting.

The claws can be retracted in sheaths to prevent them getting blunted when walking across the savannah, which they can do almost noiselessly on soft pads.

Vipers are a large family of snakes; the scientific name is Viperidae. They are found all over the world, with the exceptions of Antarctica, Australia, New Zealand, Madagascar, north of the Arctic Circle and island clusters such as Hawaii.

The family Viperidae includes adders, pit vipers (like rattlesnakes, cottonmouths and copperheads), the Gaboon viper, green vipers and horned vipers.

All vipers are venomous and have long, hinged fangs. "Generally more venomous vipers are in tropical areas, particularly South America and Africa," said Alan Savitzky, a professor of biological sciences at Utah State University specializing in the biology of snakes. Vipers found in colder, northern climates, such as the black or European adder have more moderate venom.