Nose-Horned Viper

 Nose-horned vipers are found in southern Europe through to the Balkans and parts of the Middle East. They occur in Southern Austria, north-eastern Italy, Slovenia, Croatia, Bosnia-Herzegovina, Serbia, Montenegro, Albania, North Macedonia, Greece (including the Cyclades), Romania, Bulgaria, Turkey, and Georgia. These snakes primarily inhabit dry, rocky hillsides with sparse vegetation, open woodland and scrub, and sand dunes. They may also be found in areas of human habitation, such as railway embankments, farmland, and especially vineyards if rubble piles and stone walls are present. It is reputed to be the most dangerous of the European vipers due to its large size, long fangs, and high venom toxicity. 

The most distinctive characteristic of theses snakes is a single "horn" on their snout. It grows to a length of about 5 mm (0.20 in) and is actually soft and flexible. 

The color pattern is different for males and females. In males, the head has irregular dark brown, dark gray, or black markings. A thick, black stripe runs from behind the eye to behind the angle of the jaw. The tongue is usually black, and the iris has a golden or coppery color. Males have a characteristic dark blotch or V marking on the back of the head. The ground color for males includes many different shades of gray, sometimes yellowish or pinkish-gray, or yellowish-brown. A row of indistinct, dark (occasionally yellowish) spots runs along each side, sometimes joined in a wavy band. Females have a similar color pattern, except that it is less distinct and contrasting. They usually lack the dark blotch or V marking on the back of the head that the males have. Ground color tends more towards browns and bronzes, such as grayish-brown, reddish-brown, copper, "dirty cream", or brick red. Both sexes have a zigzag dorsal stripe set against a lighter background. The belly color varies and can be grayish, yellowish-brown, or pinkish, "heavily clouded" with dark spots. Underneath, the tip of the tail may be yellow, orange, orange-red, red, or green. Juveniles are about the same color as adults.

Nose-horned vipers are solitary and depending on location can be active both during the day and night. They hibernate in the winter for a period of 2 to 6 months depending on environmental conditions. Despite their reputation, Nose-horned vipers are not aggressive and tend not to bite without considerable provocation. If surprised, wild specimens may react in a number of different ways. Some remain motionless and hiss loudly, some hiss and then flee, while still others will attempt to bite immediately.

Nose-horned vipers are carnivores. They feed on small mammals and birds. Juveniles prefer lizards. Nose-horned vipers will occasionally eat other snakes and there are also reports of cannibalism.

The mating season for Nose-horned vipers starts in the spring (April-May), right after hibernation. Before mating, the males will engage in a combat dance. This species is ovoviviparous and give birth to live young. Females give birth to 1-20 live young usually in late summer or fall (August–October). Snakelets are born fully-developed and are 14-24 cm (5.509.4 in) in total length.

This is likely the most dangerous snake to be found in Europe. In some areas it is at least a significant medical risk. The venom has both proteolytic and neurotoxic components and contains hemotoxins with blood coagulant properties, similar to and as powerful as in crotaline venom. Other properties include anticoagulant effects, hemoconcentration and hemorrhage. Bites promote symptoms typical of viperid envenomation, such as pain, swelling and discoloration, all of which may be immediate. There are also reports of dizziness and tingling. Humans respond rapidly to this venom, as do mice and birds. Lizards are less affected, while amphibians may even survive a bite. European snakes, such as Coronella and Natrix, are possibly immune. Nose-Horned Viper venom is used in the production of antivenin for the bite of other European vipers and the snake is farmed for this purpose.