1. Box Jellyfish
Box jellyfish produce extremely potent venom: Chironex fleckeri, Carukia barnesi and Malo kingi. Stings from these and a few other species in the class are extremely painful and can be fatal to humans.
Although the box jellyfish has been called “the world’s most venomous creature”, only a few species in the class have been confirmed to be involved in human deaths, and some species pose no serious threat at all. For example, the sting of Chiropsella bart only results in short-lived itching and mild pain.
2. King Cobra
King Cobra is the world’s longest venomous snake, with a length up to 18.5 to 18.8 ft. The king cobra is considered to be a dangerous snake and has a fearsome reputation in its range, although it typically avoids confrontation with humans if possible.
The venom of the king cobra consists primarily of neurotoxins, known as the haditoxin, with several other compounds. Its murine LD50 toxicity varies from intravenous 1.31 mg/kg and intraperitoneal 1.644 mg/kg to subcutaneous 1.7—1.93 mg/kg.
3. Marbled Cone Snail
The venom of cone snails contains hundreds of different compounds, and its exact composition varies widely from one species of cone snail to another. The toxins in these various venoms are called conotoxins. These are various peptides, each targeting a specific nerve channel or receptor. Some cone snail venoms also contain a pain-reducing toxin, which the snail uses to pacify the victim before immobilising and then killing it.
4. Blue-Ringed Octopus
Blue-ringed octopuses are the world’s most dangerous marine animals. They can be recognized by their characteristic blue and black rings and yellowish skin. When the octopus is agitated, the brown patches darken dramatically, and iridescent blue rings or clumps of rings appear and pulsate within the maculae.
5. Stone Fish
Stonefish is the most venomous fish currently known in the world.They are found in the coastal regions of the Indo-Pacific. Stonefishes have potent neurotoxins secreted from glands at the base of their needle-like dorsal fin spines which stick up when disturbed or threatened. Stonefish stings are both potentially lethal and extremely painful. The two most recommended treatments include the application of heat to the affected area and antivenom.
6. Death Stalker Scorpion
The deathstalker is regarded as the most dangerous species of scorpion. Its venom is a powerful mixture of neurotoxins, with a low lethal dose. While a sting from this scorpion is extraordinarily painful, it normally would not kill a healthy adult human. However, young children, the elderly, or infirmed (such as those with a heart condition and those who are allergic) would be at a much greater risk. Any envenomation runs the risk of anaphylaxis, a potentially life-threatening allergic reaction to the venom.
7. Inland Taipan
The inland taipan is considered 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.
8. Brazilian Wandering Spider
The Brazilian wandering spiders appear in Guinness World Records from 2010 as the world’s most venomous spider. Guinness World Records states that although the Brazilian wandering spider venom is the most toxic, an effective antivenom is available and few fatalities occur.
9. Poison dart frog
Poison dart frogs are brightly colored, displaying aposematic patterns to warn potential predators. Their bright coloration is associated with their toxicity and levels of alkaloids.
10. Puffer Fish
Pufferfish are generally believed to be the second-most poisonous vertebrates in the world, after the golden poison frog. Certain internal organs, such as liver, and sometimes the skin, contain tetrodotoxin and are highly toxic to most animals when eaten; nevertheless, the meat of some species is considered a delicacy in Japan and China when prepared by specially trained chefs who know which part is safe to eat and in what quantity.