The snake, however, to which the word "asp" has been most commonly applied is undoubtedly the haje of Egypt, the spy-slange or spitting snake of the Boers (Naja haje), one of the very poisonous Elarinae, from 3 to 4 ft.
A hooded snake (Naja haemachates), the imfezi of the natives, is dangerous, and spits or ejects its poison; besides this there are a few other varieties of the cobra species.
Only very few poisonous snakes (like Naja elaps) are known to resent the approach of man so much as to follow him on his retreat and to attack him.
Of these, several poisonous species exist, including the cobra and karait (Naja tripudians and Bungarus caeruleus).