A large snake with a distinct head, and very large eyes with round pupils. The body scales are keeled, in 19 oblique rows at midbody. Juveniles are twig-coloured, often with blue skin between the scales on the forebody; the head is dark brown above and white below.
They have jewel-like, emerald-green eyes and a yellow throat. Adult females are light olive or brown, with white to brown bellies. Males are more brightly coloured, and occur in various colour phases: They may be leaf-green (and sometimes powder-blue), with a light green belly and occasionally black skin between the scales; or bright green or yellow with black-edged scales, giving a cross-barred appearance, with the head vermiculted in black; or black with dark grey, black-edged belly scales; or brick-red to rust-red, with an orange-pink belly.
These snakes are dangerous but shy. They hunt during the day. Their excellent vision aids them in catching prey, with consists of small invertebrates. It prefers eating birds, raiding nests of newly hatched chicks as well as taking adult birds. Prey is actively pursued, seized and chewed to introduce the toxic venom, which quickly kills the victim. When cornerd, a boomslang will inflate its neck to expose the brightly coloured skin, and may strike.
Mating occurs in spring, and 10 to 14 (occasionally up to 25) eggs (40 x 20 mm) are laid in tree hollows or leaf litter in summer. Incubation takes 2 to 3 months. The young meassure 290 - 330 mm
Open bush and savanna; also found in sparsely woodedgrassland in de Winterberg (E.Cape).
Found throughout Subsaharan Africa, occurring in the northern parts of the region and extending along the east and south coast to Cape Town.