This large snake measures up to 140 centimetres long. It has a flat head with a sharpened nose. The upper part of its body is olive with various tints, and there are numerous dark spots or narrow cross-cut stripes on its back. It typically has a dark V-shaped spot on the back of its head. Its belly is yellowish. Unlike the grass snake it does not have a yellow "collar" behind its head.
The dice snake is found from Western France to India and Mongolia. In Ukraine, it is found in the steppes and in Crimea.
It lives in both fresh and very salinated water bodies, with either flowing or motionless water. It is active during the daylight, especially in the morning and at the end of the day. It spends most of its time in the water, but is also found warming itself in the sun on the banks. An excellent swimmer, the dice snake can cover a distance of 3 to 5 kilometres. Its diet comprises mostly fish, although it can also hunt frogs, small birds and mammals. It brumates in rodents' burrows or natural hollows, commonly in large groups of up to 200 snakes. Dice snakes mate in April. In late June females lay between four and 18 eggs, from which juveniles up to 20 centimetres long hatch at the end of August. The dice snake is entirely harmless but is often killed when mistaken for a viper.