[9] Americo-Liberians apparently call adult "puff-adders", such as the B. nasicornis, but also the B. gabonica (gaboon viper), cassava snakes.

[10] Explorer Harry Johnston (1858 – 1927) mentions in his book 'Liberia' (1906) that adult "puff-adders" of the species B. nasicornis and B. gabonica (gaboon viper) grow to "between four and five feet" (about 120 to 150 cm) in Liberia.

[10] The color pattern consists of a series of 15–18 blue or blue-green, oblong markings, each with a lemon-yellow line down the center.

A series of dark crimson triangles run down the flanks, narrowly bordered with green or blue.

The belly is dull green to dirty white, strongly marbled and blotched in black and gray.

After they shed their skins, the bright colors fade quickly as silt from their generally moist habitat accumulates on the rough scales.

[7] B. nasicornis is found from southern Guinea, Sierra Leone and Liberia[3] to Ghana in West Africa, and in Central Africa in the Central African Republic, southern Sudan, Cameroon, Gabon, Congo, DR Congo, Angola, Rwanda, Uganda and western Kenya.

Their vivid coloration actually gives them excellent camouflage in the dappled light conditions of the forest floor, making them almost invisible.

[7][5] They are slow moving, but capable of striking quickly, forwards or sideways, without coiling first or giving a warning.

[10] These adders also make a sort of hissing noise through their nose as part of their respiratory function.

Preferring to hunt by ambush, it probably spends much of its life motionless, waiting for prey to wander by.

One long-term captive specimen, regularly fed killed mice and frogs, always held on to its prey for several minutes after a strike before swallowing.

It generally feeds on smaller prey than the closely related Gaboon viper (Bitis gabonica).

[3] In West Africa, the species gives birth to between six and 38 young in March–April at the beginning of the rainy season.

This venom attacks the circulatory system of the snake's victim, destroying tissue and blood vessels.

[12] At least one antivenom protects specifically against bites from this species: India Antiserum Africa Polyvalent.