The king cobra (Ophiophagus hannah) is an elapid found predominantly in forests from India ... Despite their large sizes, typical king cobras are fast and agile. Some viper species, such as the eastern diamondback rattlesnake and the Gaboon ...The Viperidae (vipers) are a family of venomous snakes found in most parts of the world, excluding Antarctica, Australia, New Zealand, Madagascar, Hawaii, various other isolated islands, and north of the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four subfamilies are currently recognised.[2] They are also known as viperids. The name "viper" is derived from the Latin word, vipera, -ae, which means "viper".
