mamba (n.)

name of a large venomous snake of sub-Saharan Africa, attested by 1859, from Zulu (i)mamba or Swahili mamba.

"Now about snakes. I have never forgotten your quiet, dignified unbelief in my snake histories, and have taken every opportunity of finding out all I can about them; more particularly of the 'mamba' or chasing snake. It is a most vicious creature, and will chase you a mile. You must ride hard if one makes for you. It reaches sixteen or eighteen feet, and has the power of erecting itself on its tail when in pursuit of its object; then throwing itself down and rushing on twenty yards or so, and then reaiing up again: and so on, till it comes to some bush or tree, round which it throws its strong tail, and then strikes right and left at its enemies." [Journal of the Society of Arts, March 11, 1859]