European venomous snake, the common viperVipera berus. Growing on average to about 60 cm/24 in in length, it has a thick body, a triangular head, with a characteristic V-shaped mark and, often, zigzag markings along the back. It feeds on small mammals and lizards. The puff adder Bitis arietans is a large, yellowish, thick-bodied viper up to 1.6 m/5 ft long, living in Africa and Arabia.