The puff adder (Bitis arietans) is a highly venomous viper species found in savannahs and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rainforest regions.

[3] It is responsible for causing the most snakebite fatalities in Africa owing to various factors, such as its wide distribution, frequent occurrence in highly populated regions, and aggressive disposition.

Some populations are heavily flecked with brown and black, often obscuring other coloration, giving the animal a dusty-brown or blackish appearance.

[4][7] One unusual specimen, described by Branch and Farrell (1988), from Summer Pride, East London, in South Africa, was striped.

The pattern consisted of a narrow (one scale wide), pale yellowish stripe that ran from the crown of the head to the tip of the tail.

[7] Puff adders have a form of olfactory crypsis, which has been shown to make detecting them difficult for trained dogs and meerkats, both scent-based predators.

The exact nature of this ability is not known, but is hypothesized to be related to a low metabolic rate, as well as relocation after shedding and defecating.

Locomotion is primarily rectilinear, using the broad ventral scales in a caterpillar fashion and aided by its own weight for traction.

[4] If disturbed, they hiss loudly and continuously, adopting a tightly coiled defensive posture with the forepart of their body held in a taut "S" shape.

During a strike, the force of the impact is so strong, and the long fangs penetrate so deeply, that prey items are often killed by the physical trauma alone.

Their prey includes mammals (rodents [Aethomys sp., Arvicanthis sp., Mastomys sp., Otomys sp., Rattus sp., Rhabdomys pumilio, and Saccostomus campestris] and even occasionally small deer), birds, amphibians (such as Schismaderma carens), lizards, other snakes, and tortoises.

A Kenyan female in a Czech zoo gave birth to 156 young, the largest litter for any species of snake.

Kauffeld (1969) mentions that specimens can be maintained for years on only one meal per week, but that when offered all they can eat, the result is often death, or at best wholesale regurgitation.

[5] This species is responsible for more snakebite fatalities than any other African snake, due to a combination of factors, including its wide distribution, common occurrence, large size, potent venom that is produced in large amounts, long fangs, and their habit of basking by footpaths and sitting quietly when approached.

Based on the degree and type of local effect, bites can be divided into two symptomatic categories – those with little or no surface extravasation, and those with hemorrhages evident as ecchymosis, bleeding, and swelling.

In both cases, severe pain and tenderness occur, but in the latter, widespread superficial or deep necrosis and compartment syndrome are seen.

[18] Serious bites cause limbs to become immovably flexed as a result of significant hemorrhage or coagulation in the affected muscles.

Deaths can be exceptional and probably occur in less than 15% of all untreated cases (usually in 2–4 days from complications following blood volume deficit and disseminated intravascular coagulation), although some reports show that severe envenomations have a 52% mortality rate.