Inland taipan
The inland taipan is the most venomous snake in the world. Based on the median lethal dose value in mice, its venom, drop for drop, is by far the most toxic of any snake – much more so than even sea snakes – and it has the most toxic venom of any reptile when tested on human heart cell culture. Unlike most snakes, the inland taipan is a specialist mammal hunter so its venom is specially adapted to kill warm-blooded species. It is estimated that one bite possesses enough lethality to kill at least 100 fully grown men, and, depending on the nature of the bite, it has the potential to kill someone in as little as 30 to 45 minutes if left untreated. It is an extremely fast and agile snake that can strike instantly with extreme accuracy, often striking multiple times in the same attack, and it envenoms in almost every case.
Russell's viper
Russell's viper ("Daboia russelii") is a species of venomous snake in the family Viperidae. of venomous Old World vipers. The single member species, "D. russelii", is found in Asia throughout the Indian subcontinent, much of Southeast Asia, southern China and Taiwan. The species is named for Patrick Russell (1726–1805), a Scottish herpetologist who first described many of India's snakes, and the name of the genus is from the Urdu word meaning "that lies hid", or "the lurker". In Bengali this snake is called chandroborha (চন্দ্রবোড়া) since it carries lenticular or more precisely lunar marks all over its body. Apart from being a member of the big four snakes in India, "Daboia" is also one of the genera responsible for causing the most snakebite incidents and deaths among all venomous snakes on account of many factors, such as their wide distribution, generally aggressive demeanor, and frequent occurrence in highly populated areas.