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.
Sydney funnel-web spider
The lethal dose of venom in humans is not known. The lethal dose of venom from male Sydney funnel-web spiders for the crab-eating macaque ("Macaca fascicularis") is 0.2 mg/kg. Higher figures were found for other experimental animals, such as 1.5 mg/kg for two-day-old mice. The average venom yield for a male is 176 mg. "Guinness World Records" has ranked the Sydney funnel-web as the world's most venomous spider, defining the term "most venomous" as "having the venom most toxic to humans", although it has also given this title to the Brazilian wandering spider.