10 Lesser-Known Venomous Snakes 10 Water cobra Although related to true cobras, the water cobra actually belongs to a different genus and gets its name after its ability to flatten its ribs to form a “hood”, similar to that of their more famous relatives. There are two species, the best known being the ringed water cobra. Water cobras are found in Africa, and can grow up to 2.7 meters (8.86 feet) long. They are indeed mostly aquatic, never wandering far away from the water, and can remain submerged for a long time. Very venomous, but shy; will only bite if provoked. This snake is not to be confused with the Giant water cobra, or false cobra (Hydrodynastes), from South America, which, although larger, isn’t nearly as dangerous.