Batroxobin, is a serine protease found in snake venom produced by Bothrops atrox and Bothrops moojeni, venomous species of pit viper found east of the Andes in South America. It cleaves fibrinogen, similarly to thrombin. Batroxobin from B atrox is used as a drug called "Reptilase" that is used to stop bleeding, while batroxobin from B moojeni is a drug called "Defibrase", used to break up blood clots.