Vipera ammodytes is a highly venomous viper species found in southern Europe through to the Balkans and parts of the Middle East. It is reputed to be the most dangerous of the European vipers due to its large size, long fangs (up to 13 mm) and high venom toxicity. Five subspecies are recognized, including the typical form described here.
Horned viper, long-nosed viper, sand viper, nose-horned viper, horn-nosed viper.
V. ammodytes grows to a maximum length of 95 cm, although they usually measure less than 85 cm. The females are somewhat smaller. Maximum length also depends on race, with northern forms distinctly larger than southern ones. According to Strugariu (2006), the average length is 50-70 cm with reports of specimens over 1 m in length. Females are usually larger and more heavily built, although the largest specimens on record are males.
The most distinctive characteristic is a single "horn" on its snout, just above the rostral scale. This horn consists of 9-17 scales arranged in 2 (rarely 2 or 4) transverse rows. The rostral scale itself is wider than it is long. The head is covered in small, irregular scales that are either smooth or only weakly keeled, except for a pair of large supraocular scales that extend beyond the posterior margin of the eye. 10-13 small scaled border the eye and two rows separate the eye from the supralabials. The nasal scale is large, single (rarely divided) and separated from the rostral by a single nasorostral scale.
The body is covered with strongly keeled scales in 21 or 23 rows (rarely 25) mid-body. The scales bordering the ventrals are smooth or weakly keeled. Males have 133-161 ventral scales and 27-46 paired subcaudals. Females have 135-164 and 24-38 respectively. The anal scale is single.
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 in color. Males have a characteristic dark blotch or V marking on the back of the head that often connects to the dorsal zigzag pattern. The ground color for males varies and includes many different shades of grey, sometimes yellowish or pinkish grey, or yellowish brown. The dorsal zigzag is dark grey or black, the edge of which is sometimes darker. 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 is variable and tends more towards browns an bronzes, such as grayish brown, reddish brown, copper, "dirty cream", or brick red. The dorsal zigzag is a shade of brown.
Both sexes have a zigzag dorsal stripe set against a lighter background. This pattern is often fragmented. The belly color varies and can be grayish, yellowish brown, or pinkish, "heavily clouded" with dark spots. Sometimes the ventral color is black or bluish gray with white flecks and inclusions edged in white. The chin is lighter in color than the belly. Underneath, the tip of the tail may be yellow, orange, orange-red, red or green. Melanism does occur, but is rare. Juveniles color patterns are about the same as the adults.