The water snake viperine (Natrix maura) it is one of the two species of snake of amphibious habits that there is in the Catalonia. He/she differs of the other species of amphibious customs, the necklace snake (N.natrix) in that the youths of this last one present a clear fringe around the neck, by way of necklace. The same as the necklace snake, the water snake viperine if discharge is manipulated the smelly content of the anal gland. It can also feign to be dead. It ends up measuring 100 cm of longitude, although it doesn’t usually pass of the 70 cm. it usually finds close it to him or inside the water, where he/she finds the amphibians, fish and spineless aquatic of those that he/she feeds preferably. It can hibernate from November to March, but it can be active with even quite low temperatures, at the beginning of spring. The name of water snake viperine is due to the behavior of imitation of the vipers and the dorsal drawing in zigzag similar to of these vipérids which can present. When it is threatened, it dilates the later part of the area of the jaws so that the head it adopts the typical triangular form of the vipers, and he/she whistles and it blows as these.