The total length of these snakes is up to 1.2-1.5 m. Some individuals reach 1.8-1.9 m. Females are usually somewhat larger than males. The body is massive, thick. In appearance, they are very similar to poisonous snakes of the genus Shchitomordnik . They differ from them by 2 lines of scales on the ventral side of the tail, a round pupil and the absence of small fossae under the eyes characteristic of muzzle. Coloring is not bright, mainly brown, dark gray or olive with dark spots or transverse stripes on the body. Scales on the back with distinct keels.
They love near-water biotopes, spend most of their lives in water. Almost everyone prefers standing or slow-moving fresh water bodies, but is also found in brackish waters of estuaries and sea bays. In the afternoon they love to bask in the sun on the branches of trees or bushes hanging over the water, from where, at the slightest danger, they fall into the water. They feed on fish, amphibians, and on occasion they do not shun rodents.
These are ovoviviparous snakes. Mating occurs in the spring. In August-September, the female gives birth to 90 cubs.
