They're truly beautiful creatures. The names comes from the insides of their mouths being back.
They are considered one of the world's most dangerous snake.
They are found in many parts of Africa and can be found in many different types of habitats, including; savanna, woodland, and rocky outcrops.
They are the second largest venomous snake in the world (behind the king cobra) and the largest in Africa. They average at about 8.2 feet but have been known to reach 14 feet. The one I saw today was about 10 feet (at a guess).
They are also the world's fastest land snake, they can reach speeds of 12 mp/h.
When they hunt mambas deliver 1 or 2 strikes to land mammals and will strike and hold on when catching birds. But when defending themselves from larger animals (such as humans) they will deliver as many strikes as possible, they can strike as many as 12 times in a row. A single strike contains enough venom to kill up to 25 men.
All in all, it's pretty clear why it's considered one of the most dangerous snakes in the world.
So if you ever happen to some across one; RUN THE FUCK AWAY!!