The olive whip snake, or olive grass snake (Psammophis mossambicus), is a venomous but non-lethal colubrid snake. It reaches a length of 1 m (3 ft 3 in) on average, but some specimens can reach up to 1.8 m (5 ft 11 in). It is typically olive-brown above with black edged scales that may form a faint black line along the back. Some individuals have scattered black scales on the neck and chin. Underside can be white to yellow. There is often a pale to yellow scale just in front of the eyes. It can be confused with the far more aggressive and dangerous black mamba (Dendroaspis polylepis).
The olive whip snake prefers moist savannahs and lowland forests. It is quite often found near water and likes to hunt in marshes. It keeps mostly to the ground, but will sometimes get to higher ground to bask in the sun. It is mostly active during the day. It will hunt and eat small mammals, lizards, frogs and other snakes. It will even eat dangerous snakes, such as the black mamba and puff adder.
The olive whip snake is venomous but a bite is not dangerous to humans. It can cause local pain, swelling and sometimes nausea. If someone gets bitten and the snake is identified as an olive whip snake the patient should still be taken to the hospital to have any symptoms treated. This is a fast and nervous snake that tends to flee quite quickly when sensing danger, and if it does not see a way out it will readily bite.
The female olive whip snake will usually lay 10-30 eggs at the height of summer. Eggs hatch after 65 days. The young will be 27-30 cm (10.5-12 in) when hatched. It is likely to live to up to 10 years.
The olive whip snake has a wide distribution in southern and eastern Africa. In South Africa it is only found in the very north and along the east coast of KwaZulu-Natal. It is not found in the more drier regions of southern Africa, such as the Kalahari, the Karoo and the Namib. It is not yet listed on the IUCN Red List, but it is not believed to be threatened.