: any of several venomous elapid snakes (genus Dendroaspis) of sub-Saharan Africa that are related to the cobras but lack a dilatable hood; especially: a southern African snake (D. angusticeps) that has a light or olive-green phase and a black phase, that attains in the latter phase a length of 12 feet (3.66 meters), and that is noted for the quickness with which it inflicts its often fatal bite
East African green mamba (Dendroaspis angusticeps).—E.S. Ross
Any of four or five species of slender, agile elapid snakes (genus Dendroaspis, or Dendraspis) having large scales and long front teeth. They inhabit sub-Saharan Africa, where they hunt small animals. The aggressive black mamba (D. polylepis), up to 14 ft (4.2 m) long, may be dull gray, greenish brown, or black, depending on age. It dens in rocky open country. It rears up to strike, biting a person's head or trunk. Its bite is nearly always fatal without antivenin treatment. The green mamba (e.g., D. angusticeps) is smaller (to 9 ft, or 2.7 m), more strongly arboreal, and less aggressive.