Hagen's Pit-viper

Hagen's pit viper, also called Hagen's green pit viper, is a venomous snake in the subfamily Crotalinae of the family Viperidae, native to Southeast Asia (now often placed in the genus Parias). It is named in honour of the German naturalist Bernhard Hagen, who collected in eastern Sumatra. It is found in peninsular Thailand and Malaysia, East Malaysia (Borneo) and Indonesia (Sumatra and nearby islands including Bangka, Simalur, Nias, Batu and the Mentawai Islands), and its preferred natural habitat is forest at 100–300 m (Wikipedia, general species account).