Mamba, a poisonous snake of tropical and southern Africa. It is related to the cobra, but, unlike the cobra, cannot expand its neck into a hood. There are several species, the largest measuring about 14 feet (4.3 m) in length. Most mambas are green, marked with black or brown. They typically live in trees or bushes, travel rapidly, and are aggressive. Their bites are usually fatal to humans. The largest and most feared species, the black mamba, is green when young, black in the adult stage. It is widely distributed. The smaller green mamba is found chiefly in the east and southeast.

The black mamba is Dendroaspis polylepis; green, D. angusticeps. Mambas belong to the family Elapidae.