The Black Mamba is long and slender, but become bulky when growing larger. Adults reach 2 to 2.5 m on average, but may reach 4.3 m. The head is coffin-shaped and slightly distinct from the neck. The pupil is round and is narrowly edged with gold, and the iris is dark-brown or grey. The inside of mouth is blue-grey to blackish. The snake’s colour is light- to dark-grey, dull-black or shades of brown or olive with light banding towards the tail. The Black Mamba’s belly is paler below or heavily mottled towards the tail. They grow very dark to almost-black just before shedding, but never pitch-black. The have smooth, dull dorsal scales in 23 – 25 oblique rows at mid-body with paired subcaudal scales and the anal shield is divided.
Fixed front fangs, 6.5 mm long, on elongated maxillary bones.
The venom is a fast-acting neurotoxin. Paralysis can occur in 15 – 45 minutes after bite and death from 3 – 15 hours. The lethal dose for an adult is 10 mg and the venom yield from a Mamba is 80 – 140 mg and up to 240 mg in specimens over 3 m long. The fatality rate in untreated bites is 70%. A BITE FROM THIS SNAKE IS A REAL MEDICAL EMERGENCY. Polyvalent anti-venom is available.
They inhabit low-lying, dry, open savanna of up to 1500 m.a.s.l. The Mamba seeks out holes underground, among rocks or under old tree stumps, often shared with members of the same or other species.
It is a shy snake but highly alert and with keen eyesight. They avoid human contact and rarely features in snakebite, accounting for 0.5 % – 2.0 % of bites. When approached it lifts it’s head well off the ground (about 1/3 of body length) for a better view. It can flatten the neck into a slight hood, while producing hollow-sounding hisses, gaping the mouth to display the black inner lining. If the aggressor steps any closer it will result in a forward lunge to bite, sometimes striking twice in quick succession. Many dogs often get killed in self-defense.
The snake is diurnal, and emerges early in the morning to bask before foraging for warm-blooded animals like rodents including young Cane Rats, young Rock Rabbits, squirrels, bats and birds. They return to a permanent refuge by late afternoon. They often enter buildings in search of rodents, chicks or aviary birds. A Mamba may take up residence in ceilings, gaining access from nearby trees.
This snake uses speed to flee rather than attack. Their average speed is 7 – 10 km/h and can reach up to a maximum of 15 – 20 km/h over a short distance, especially if moving downhill. They might deliver defensive bites to legs when they are accidentally stepped on in long grass.
Black Mambas reproduce by laying eggs.