|Distribution of B. arietans|
The Puff adder is one of the largest vipers in the world. The name may refer to the species (B. arietans) or any member of the taxonomic genus Bitis. The Afrikaans also call it the 'pofadder'. This adder can be found in most parts of Africa. Their most famous attribute is their potent venom and the effects they have on their victims. When coming across one they appear very distinct by their thick bodies and unusually proportioned small tail. Their name 'puff adder' is derived from their behavior exhibited when become agitated and ready to strike; they puff up their bodies and hiss as a sign of caution.
This adder is famous for not only being the heaviest viper in the world, but also the second largest. This snake was found to grow up to 7 feet.  Although they may have extremely large bodies, their tails are quite short in comparison. Their heads are very broad and triangular shaped with its snout being one of the points. On their snouts they have nostrils that face upward, vertically. Their mouths hold razor sharp teeth.  Two of those teeth are especially dangerous because they are hollow and hold the venom. Their curved, needle-sharp fangs are located in the front of their mouth. They can grow up to 2cm long. This will better ensure a strong dose of venom because it can penetrate deep within the victim.  A well developed solenoglyphous (venom delivery system) also helps in a lethal bite.  They have strong keeled scales all along their body containing 20-41 rows at the midbody. On the underside of the snakes they have large scales that are as wide as the body. There are 124-147 of these. In the subcaudal (underside of the tail) there are 16-37 of these broad, type scales. 
The snake's skin coloring can vary from light yellow to a brown, gray, or even an orange-brown shade. The ventral side is a yellowish white coloring and can sometimes be found with some spots.  On the head there can be found two distinct dark spots that starts at the eye and goes to the jaw.  Unlike the body, on the ventral side of the tail there are dark bands. Every snake has a specific skin design, and the puff adder for example has a chevron pattern. Whenever the snake is about to shed its skin their coloring will become very dull. Once it has completed its shedding, their coloring and skin will be much brighter and more distinct. 
Being a limbless creature, the puff adder, unlike most other snakes, moves in a rectilinear motion, much like that of a caterpillar. Although, when it is agitated it will move in the more common serpentine fashion.  When this adder is about to strike a potential victim, it will go into a very distinct striking position. It will lift its front end off of the ground a small amount and point its head down with its nose facing the ground. Their bodies will inflate, causing it to puff up. What people usually notice when a puff adder is ready to strike is the loud, deep hiss that it emits as a warning. Once it feels that it will no longer be disturbed it will slowly back away. It will continue to hiss until it finally moves away. 
The puff adder snake is an ovoviviparous animal.  This means that they bear live young after developing in eggs inside the mother's body. During birth a female may give birth to around 70-80 at a time.  Sometimes though, a normal batch may be around 20-40. The puff adder holds the record for the largest birth of offspring at 156 young.  When the young are born they come out of the mother's body in egg-cases. The young break free of their leathery confinement almost immediately, almost within minutes of their birth. When they are born the young look exactly like the adults, just in a smaller form.  When they are newly born they are approximately 15-20cm long.  This snake will be found giving birth starting in the late summer until early autumn. 
For the puff adder, mating season begins right after the young are born, in late autumn and runs all the way until early spring. During this time the males will fight over the females for the right to mate.  The males will not only become active in fighting, but also in their environment. In their search for mates they will roam around the land. Once the season begins they won't settle down for a long while. Because it is mating season this snake, like most other animals, may become more sensitive toward others. They will be more aggressive and likely to strike if they feel even the least bit threatened. 
The puff adder is the most widespread snake out of the different species of snakes in Africa. They can be found from the southern Cape to southern Morocco and south Arabia. Aside from these, the most populated area that they inhabit are most spots in southern Africa. They do their best to avoid places such as extreme deserts like the Sahara, dense forests like tropical rain forests, and high altitudes above 2000 meters high.  They aren't only comfortable on land, but also in the water, like most other snakes. They will swim on the surface, moving in serpentine patterns. They may be found simply resting in the water with only their heads poking out for long periods of time. 
Many times these snakes can be most likely found on or on the side of roads. When it is approached they normally don't move or slither away; they stay very still. This is why most people get bitten. People don't see it when they are walking about and they accidentally step or touch them unknowingly and are struck.  They remain motionless when coming in contact with potential danger because they are relying on their camouflage to protect them, hoping they will be ignored. The only time they will strike a human is when physically disturbed. When they do strike they will strike with astonishing speed and with great force. 
A puff adders venom is cytotoxic which means that it is cell-destroying. Even though it is a cytotoxic venom, the effects it has on the victim is also haematoxic (causes internal bleeding due to blood-clotting mechanism) and even some cardiotoxic (affects the heart). The venom is injected in very large volumes by the long fangs.  In a single bite there is 100-350mg injected within a victim. A lethal dose for a human would be around 100mg. There are several symptoms following a puff adder strike such as: intense pain, massive swelling, abdominal cramping, high fever, in and out of shock, breathing difficulty, extensive subcutaneous bruising, and major blood blisters.  The venom is slow-acting and will take up to 24 hours for fatalities.  If a person were to die quickly after the bite, the normal, main cause would either be from circulatory collapse, anaphylactic shock, or organ failure due to intense swelling. Even if a person doesn't die right away that doesn't take the risk away. There is still a chance of death 2-4 days following the bite because of blood volume deficit or the development of dissemination intravascular coagulopathy. Most of the time if there is no death in a situation, it is most likely that the patient will have some sort of disfigurement or disability due to the envenomation anywhere from the loss of a nail or a limb. 
Since the snake is so common within Africa it isn't a surprise that approximately 60% of all snakebites are caused by the puff adder. Its bite is the leading cause of death by snakes in Africa.
- Snakes of South Africa Dr. V. F. M. FitzSimons.
- The Puff Adders Den.
- Wikipedia many authors.
- Puff Adder/Pofadder Ricardo Davids. SCARCE.
- Puff Adder Department of Vertebrates. Transvaal Museum.