9. Fer-de-lance

A bite from a fer-de-lance (Bothrops asper) can turn a person's body tissue black as it begins to die, according to a 1984 paper published in the journal Toxicon. These pit vipers, which live in Central and South America and are between 3.9 and 8.2 feet (1.2 and 2.5 m) long and weigh up to 13 pounds (6 kg), are responsible for about half of all snakebite venom poisonings in Central America, according to a 2001 study published in the journal Toxicon.

10. Black mamba

Black mambas are some of the scariest snakes on the planet. Named for the dark, inky color inside of their mouths, black mambas are actually brownish in color. They average around 8 feet (2.5 meters) in length.Fast and deadly, these blue-tinged snakes are thought to be responsible for up to 20,000 deaths a year, though precise numbers are hard to come by.

11. Eastern brown snake

Eastern brown snakes are endemic to eastern Australia and are responsible for more human fatalities than any other snake species in the country. Their venom is highly potent, containing powerful toxins that can cause paralysis and internal bleeding. The initial bite is often painless, according to the Australian Museum. 

"They're the only snakes in the world that regularly kill people in under 15 minutes," Bryan Fry, who studies venom at the University of Queensland, told ABC News in 2024. "Even more insidiously than that is that for the first 13 minutes, you're going to feel fine."

They generally hunt during the day and are often found in the suburbs of cities and large towns, putting them in close contact with humans. Many eastern brown snake bites are the result of people trying to kill them.  Read More »

12. Common death adder

Common death adders are found across coastal areas of southern, eastern and northern Australia. They are recognizable thanks to their broad, triangular heads, short, thick bodies and thin tails. Common death adders are ambush predators and wait for prey — including frogs, lizards and birds — under leaves until they are ready to strike. 

Bites to humans are rare and normally involve a person stepping on one by accident. Their venom causes paralysis and can lead to death: Before the introduction of antivenom in the 1950s, about 60% of bites were fatal, according to the Australian Museum. The most recently recorded human fatality from a common death adder bite was in 1930.