Adult Black mamba snakes have an average length of 2.5 metres (8.2 feet) and a maximum length of 4.5 metres (14 feet). The Black mamba snake receives its name from the black colouration inside of its mouth, rather than their skin colour which is a grey to olive tone. The Black mamba snake is the fastest moving snake in the world, capable of moving up to 20 kilometres per hour (12.5 miles per hour). However it uses this speed to escape danger, rather than catch prey.

Black mamba snakes live primarily in scrub land and though not considered an arboreal species, can live in bushes and small trees.

Black mambas spend their nights in holes in the ground, usually disused burrows or hiding deep among fallen rocks or timber. These hiding places are also fled to by the snake if it becomes alarmed and it will attack any creature blocking the path to its hole.

Like all reptiles, the black mamba snake is cold blooded and relies on external heat to maintain its body temperature. Therefore, it frequently basks in the sun during the day, either on a low branch or a rock, however, during the summer, the snake may be forced to take cover in its burrow if it becomes too hot.

Breeding usually takes place in late spring or early summer. After mating the male will return back to its own home. The female will then lay between 10 and 25 eggs, usually in decaying vegetation. The decomposition of the vegetation gives off heat, which helps to warm the eggs and speed up hatching time. The shells of the eggs allow water and oxygen to reach the developing embryos.