Redback spider© Ian Waldie/Getty Images
Generally found in Australia, these spiders carry lethal neurotoxins that can cause serious harm to a human body and may kill a person if there is no anti-venom available for treatment. Most bites occur during summers and are inflicted by the female redbacks as they are more toxic, larger in size and survive four times longer than a male redback.
Deathstalker scorpion© imageBROKER/REX/Shutterstock
These are very aggressive scorpions that primarily reside in North Africa and the Middle East and cause more than 75 percent of deaths related to scorpions every year. Adults usually feel unbearable pain from a sting, but children are at risk of death, as they may become paralyzed and suffer from fever, coma and convulsions before their lungs fill up and cut off the flow of air.
Brazilian wandering spider© Guenter Fischer/imageBROKER/REX/Shutterstock
According to the Guinness Book of World Records in 2014, these spiders were the world's most venomous, and a drop of their venom is enough to take a life. What makes it a bigger threat to humans is that when the arachnid is not actively hunting or wandering, it hides in densely populated areas. These hiding spots can be homes, cars and shoes, leading to encounters with people.
Box jellyfish© AP Photo/marinethemes.com, Kelvin Aitken
Arguably the world's most venomous animal, the box jellyfish has killed more than 5,000 people since 1954. Its overpowering venom attacks the heart, nervous system and skin. They can be found widely in tropical and subtropical oceans.
Blue-ringed octopus© FLPA/Colin Marshall/REX/Shutterstock
Found in the tide pools in the Pacific Ocean, the octopus can easily kill more than 25 people within minutes with the venom it contains. There is no anti-venom available for its poison, which makes the blue-ringed octopus one of the most dangerous marine animals.
King cobra© FLPA/Malcolm Schuyl/REX/Shutterstock
This reptile is the longest venomous snake inhabiting southern Asia, and it can kill an elephant with a single strike in minutes, injecting five times more venom than a black mamba.
Puffer fish© Andrey Nekrasov/imageBROKER/REX/Shutterstock
Puffer fish are known to be the second-most poisonous vertebrates and can cause a rapid death. Surprisingly, people eat puffer fish in Japan and Korea, but only licensed chefs are allowed to cook them.
Cone snail© Franco Banfi/Getty Images
Also known as the cigarette snail, they can take 20 human lives within a few minutes with a drop of their venom. These snails are usually found in warm and tropical seas in the Mediterranean or western Indo-Pacific regions.
Poison dart frog© imageBROKER/REX/Shutterstock
These frogs breed in the humid, tropical environment of Central and South America, and are found in several colors including yellow, blue, green and red. They don't inject poison through their mouth but through their skin, so even touching these frogs may lead to sudden death.
Carpet viper© imageBROKER/REX/Shutterstock
This species is known to be the cause of most snake-related deaths in Asian and African nations, and interestingly, the venom of a female viper is twice as toxic as that of a male.