Yes.
Sea snakes, adders, cobras, water mocassins, mambas, rattle snakes, boomslangs...
No, not all colubrids are non-venomous. Some species of colubrids, like boomslangs and twig snakes, are rear-fanged and possess mild venom that they use to subdue their prey. It's important to take caution when handling any snake species, as some colubrids can still deliver a venomous bite.
They are endangered
Not all snakes are venomous. Of the 3,500 snake species - only around 400 are actually venomous, AND of those, only a small number are actually lethal to humans !There are around 650 venomous species with JUST Elapidaeand Viperidae. That's not including your venomous Colubrids (e.g. Boomslangs, Mangrove snakes, and other opisthoglyphs, though most rear-fanged snakes are of little to no consequence to humans, admittedly).
A boomslang is a venomous snake native to sub-Saharan Africa. It is known for its large eyes and back-fanged teeth that can deliver a potent haemotoxic venom. Boomslangs are arboreal snakes, meaning they are primarily found in trees.
Snakes of the genera Atheris (bush vipers), Bothriechis (palm-pitvipers), and Bothriopsis (forest-pitvipers) are all uniformly arboreal and very venomous. There are also the Mambas of Dendroaspis (literally means "tree snake") and a majority of cobras are semi-arboreal. There are also snakes like Mangrove Snakes and Boomslangs that are technically obscenely venomous but have a poor delivery system as they are rear-fanged.However, there are as many (if not many more) non-venomous species of snakes. That should not be taken to mean that being bitten by such a snake is not serious, many boas and pythons have very nasty bacteria that can lead to dangerous infections.
Boomslang (or "tree snake") are mainly tree dwelling and are found mainly in southern Africa
Venomous.
They are not venomous.
Average adult length ranges from 42-60 inches, though as with all animals, exceptions can occur.
No, they are not venomous.
Non-venomous