The present snakes are of medium size, although individual individuals can reach 1.2-2.4 meters in length. Characterized by scales with distinctly expressed ribs, triangular mezhnosovymi scutes, divided by an anal scute. Teeth on the maxillary bones increase in size in the direction of the mouth, the last 1-2 teeth are the largest. The pupils are round, the nostrils are directed to the sides and upwards. Abdominal side, as a rule, spotted.
Most of the snakes inhabit wet biotopes and are more or less connected with water bodies. Dins well swim and dive, can stay under water for a long time. They feed mainly on amphibians, fish, much less often - small mammals, birds and invertebrates. Extraction is swallowed alive without killing.
Eggs are laid in heaps of rotting plant debris, manure, wet moss, under objects lying on the ground, into holes.