An animal’s rating on the most-venomous scale is subject to a lot of possible variances. Some animals may have incredibly potent toxins, but they are harmless to humans. Some creatures may be very venomous but are shy or have little access to humans. The potency of a toxin has to be weighed against the amount injected. The number of deaths has to be weighed against the overall mortality rate.
The animals on this list are a collection of the most venomous animals with all that considered.
There are not many venomous lizards that pose a threat to humans, but one of the most well-known is the Gila monster. The Gila monster is the most venomous of all lizards native to the US and Mexico. While its bite does not lead to death, the toxin is a mild neurotoxin and bites are very, very painful.
Another venomous lizard is the Mexican beaded lizard. This lizard delivers its venom by chewing on its prey. Venom is released via glands in its mouth and distributed by the lizard’s grooved teeth. Very rarely bites do lead to death by respiratory failure.
Many different spiders are venomous and use their toxin as a way to subdue and kill prey. The black widow is one species that can be dangerous to humans. Black widows have huge venom glands that deliver very concentrated venom. While these bites can be fatal, it is not common if treated early. Bites are severely painful and can lead to loss of muscle control.
The funnel web spider has a toxin that is twice as deadly as cyanide. A bite can lead to decreased blood pressure, hemorrhaging, arrhythmia, coma, and even death.
Fish can be both poisonous and venomous. One of the more venomous fish species is the stonefish. Because of their camouflaged body, stonefish are most commonly stepped on by swimmers and divers. Stonefish have needle-like defensive dorsal fins that deliver a very painful and sometimes lethal sting. If left untreated, a human could die within six hours of being stung.
Stingrays are all venomous to some degree, but the blue-spotted stingray is the most venomous of them all. Even so, blue-spotted stingrays rarely kill humans. The exception is when the ray’s stinger enters the abdomen or chest, allowing toxins to get to the heart or other vital organs.
Mollusks encompass everything from sea snails to squids and many of them are venomous to some degree or other. The cone snail is a mollusk that has a very potent venom with a lethal dose that is incredibly small. While few humans are ever stung by the cone snail, the potent venom in just one snail could kill up to 20 adult humans. Cone snails hunt with harpoon-like stingers, paralyzing fish and eating them alive. A sting can lead to muscle paralysis, respiratory failure, vision impairment, and sometimes death. Divers who handle them are most often stung since the snail’s sharp, hollow teeth can penetrate a wetsuit.
The blue-ringed octopus is a tiny sea creature, about the size of a golf ball. But its toxin is deadly. A sting can lead to respiratory failure within 10 minutes and death within 30 minutes. There is no known antidote.
Snakes are well known to be venomous. For example, the inland taipan is an Australian native that has the highest median lethal dose of any snake or animal on the whole planet. A single drop can kill up to 100 people and could work in as little as 4 minutes. However, the inland taipan is a shy snake that does not encounter humans often, so while it is one of the most venomous animals, it is not the most dangerous.
The black mamba is not only one of the most venomous snakes but is also the fastest-moving snake. These snakes can move up to 14mph, faster than most humans. Their venom is a mix of neurotoxins and cardiotoxins which can kill a person in as few as 7 hours. The king cobra has the fastest-killing venom which can kill a person in as few as 30 minutes. It doesn’t have the most potent venom but it can “spit” its venom and the effects are deadly.
Jellyfish have the deadliest combination of venom, potent and fast-acting toxins. The box jellyfish is not only one of the most venomous creatures in the world, but it is also one of the deadliest. The toxins are transferred via millions of nematocysts on the jellyfish’s almost transparent tentacles. The sting is extremely painful, and the toxins target the heart, nervous system, and skin cells. Swimmers who are stung quickly go into shock, often drowning or dying due to heart failure before they can even get back to shore. Victims can experience delirium, paralysis, shock, cardiac arrest, and death within minutes of being stung.
The Irukandji jellyfish is another venomous jellyfish, but one so small that it is barely the size of a fingertip. Yet, the painful testing of these jellyfish causes Irukandji Syndrome which can lead to fatal brain hemorrhages. There is no antidote for this venom and the pain is resistant to the effects of morphine.