The boomslang (ˈboʊmslɑːŋ, ˈbɔːmsləN, or ˈbuːmslæŋ; Dispholidus typus) is a large, highly venomous snake in the family Colubridae. Its common name means "tree snake" in Dutch and Afrikaans – boom meaning "tree", and slang meaning "snake". In Afrikaans, the name is pronounced ˈbuəmslaŋ. The boomslang is thought to be closely related to members of the genera Thelotornis, Thrasops, Rhamnophis, and Xyelodontophis, with which it forms the taxonomic tribe Dispholidini. Two subspecies are recognised, including the nominotypical subspecies. D. t. kivuensis D. t. typus The trinomial authority in parentheses for D. t. typus indicates that the subspecies was originally described in a genus other than Dispholidus. The average adult boomslang is in total length. Some exceed . The eyes are exceptionally large, and the head has a characteristic egg-like shape. Colouration is highly variable. Males are light green with black or blue scale edges, but adult females may be brown; this demonstrates as sexual dimorphism. Weight varies from , with an average weight of . In this species, the head is distinct from the neck and the canthus rostralis is distinct. The pupil of the very large eye is round. The boomslang has excellent eyesight and often moves its head from side to side to get a better view of objects directly in front. The maxillary teeth are small anteriorly, seven or eight in number, followed by three very large, grooved fangs situated below each eye. The mandibular teeth are subequal. The body is slightly compressed. The dorsal scales are very narrow, oblique, strongly keeled, with apical pits, arranged in 19 or 21 rows. The tail is long, and the subcaudal scales are paired. Ventral scales are 164–201; the anal plate is divided; and the subcaudals are 91–131. The boomslang is endemic to sub-Saharan Africa. It is found in South Africa, Eswatini, Mozambique, Botswana, Namibia and north through sub-Sahara Africa. The boomslang is an excellent climber and is highly arboreal, living mainly in forested areas. D.