The world's deadliest snakes in terms of annual human casualties through snakebite include the saw-scaled viper, the ocellated carpet viper, the Indian krait, the Indian cobra and the Russell's viper. Among the snakes with the deadliest venom are the inland taipan, the eastern brown snake, the black mamba, the king cobra and various types of sea snakes.
Although the saw-scaled viper is often less than a foot long, it is responsible for more deaths, especially of agricultural workers in India and Sri Lanka, than any other snake as of 2015. The ocellated carpet viper is a similar two-foot-long viper that kills thousands of people annually in western Africa. The Indian krait, whose bite is not painful but causes quick paralysis and respiratory failure, sometimes invades houses in India and bites the inhabitants as they sleep. Because the Indian cobra frequents inhabited rural areas, it often bites humans, causing death by paralysis. The bite of the Russell's viper causes pain, swelling, tissue damage and death to victims in Pakistan, Sri Lanka, Indonesia, Taiwan and other Asian countries.
Some scientists credit the inland taipan of Australia with the deadliest venom on Earth, although it kills few humans because it is reclusive and lives in isolated areas. Other scientists claim that venomous sea snakes are even more deadly than the taipan, but these also seldom bite humans. Highly venomous eastern brown snakes account for most snakebite deaths in Australia, but the numbers are miniscule compared to deaths by snakebite in other countries. The black mamba, which grows up to 10 feet long and is the world's fastest snake, has venom that can kill a human in 30 minutes to a few hours. The king cobra, the world's largest venomous snake, can kill an elephant with its venom.