The black mamba is huge, with a body length of about 60cm at birth, a total length of 2.5~3.2m, and a weight of 1.6~3.1kg. The largest recorded length of the black mamba is 4.48m. The black mamba has a coffin-shaped head and is easily recognizable. The most recognizable feature of the black mamba is its jet-black mouth, which is its best warning message when threatened. The eyes of the black mamba are mostly brown or black. These can be easily hidden.

The body color of the black mamba is seldom black, mainly including Gray, gray-blue, dark green, brown, brown, khaki, etc., while the young black mamba is mainly bright gray or dark green. The name Black Mamba comes from its black mouth. The abdomen is white, and some are beige. In addition, some black mambas have light-colored stripes on their bodies.