Many ignorantly assume that a Cassowary will be a lot like an Emu. While the two are semi-related, they act VERY differently toward humans. Often referred to as today’s version of a raptor, cassowaries are known as “the most dangerous bird on the planet.” This is for a legit reason, they do not mind attacking anyone or anything. Most of the time, one would assume if you feed an animal that comes up to you, they will leave you alone and focus on the food.
Cassowary might do that, but when humans feed them they begin to expect it. As a result, they have attacked humans for food they might have on them. A study conducted in 2003 looked into 221 cassowary attacks. 75% of them were cassowaries that were fed by. 71% of the time the bird chased or specifically charged at them and 15% of the time they kicked. 150 of these attacks were on humans while the rest were on other animals. Some deaths have occurred from cassowary attacks, but there has not been one since 2019.
Bull Sharks are one of the few shark species in the Australian region that actually attack humans just because. Yes, bull sharks can be found elsewhere but they do seem to love it around the Aussies. The weird part is that this is both a saltwater and freshwater shark. This is referred to as a diadromous species, or one that spends time in both freshwater and saltwater. In case you thought rivers and lakes were safe, now you know better!
That makes them a problem in a place like Australia that is surrounded by both freshwater and saltwater territories. They love to swim in shallow waters, making it easy to bump into humans. These sharks have attacked swimmers in the Sydney Harbour alone! You’ll often see them swimming in waters of 100 feet or less in terms of depth. That is often why they attack humans quite a lot annually. Remarkably, sharks attack a lot but do not tend to kill many humans.
While the Portuguese Man O’War is not technically part of any one country specifically, they sure do love Australia. They can be found all over the region, and are often confused for other things. Due to their unique look, some assume they are a toy or plastic and mistakenly pick them up. They also love to hang around random areas of the ocean, sometimes even near shorelines. That is why they tend to sting around 10,000 people in Australia annually!
While they do sort of look like jellyfish, they are actually a siphonophore. These creatures appear to be one individual organism but when you look closely, they are actually a major colony of organisms. The Man O’War is composed of medusoid and polyploid zooids that have morphed together and function to do specific jobs. It’s absolutely fascinating, but the creature is one of the deadliest animals in Australia today! They inject painful venom that is enough to kill some humans.
While some might say that a tick should not be completely feared, we feel you should specifically be afraid of the Australian Paralysis Tick. Why? It’s pretty simple. The tick actually operates like any other normal tick. But instead of simply biting in to suck up blood, they include a neurotoxin in their bite. The toxin makes it to where you won’t feel them biting into you, allowing them to stick around longer. Most humans do not have life-threatening interactions with the tick.
However, some can be allergic to them and have a reaction. The real thing to worry about for all humans is a specific tick-transmitted infectious disease known as Rickettsial Spotted Fever. While not always deadly, it can be for some but it typically can give people flu-like symptoms. Another issue they cause is tick paralysis, which can give humans some severe respiratory trouble and sometimes a lack of mobility. Any of these issues are worthy of immediate medical attention.
Tasmanian Devils at one point were nearly going toward the way of their cousin, the Tasmanian Tiger. They were slowly dwindling in number but thankfully proper breeding programs have prevented their major decline. How are these little devils some of the deadliest animals in Australia? First, you should know that many like to work in packs to take down animals. They do not mind going after a creature larger than them, but this is due to the powerful weapons they possess.
They have teeth that can rip through just about anything, as well as claws that are perfect for digging into the ground or into tough skin. Do they tend to go after humans? No. In fact, they rarely have contact. But when they do, it is often due to one getting in the road and being run over accidentally. The devils are often aggressive the most when it’s feeding time, but they are not like this 24/7. However, they are still dangerous and “could” kill people but don’t. At most, they just injure us.
While Lionfish are slowly becoming an invasive species in the Americas, they are traditionally from the Australian region. In fact, they had been native to the coral reef there. Currently, NOAA and its partners are trying to fix the issue and move more lionfish back to the reefs. Lionfish serve a great purpose to reefs due to removing pests that cause the reefs harm. They are feared fish in the ocean for an understandable reason. They possess venomous spikey fin rays.
These rays are filled with venom that has negative inotropic and chronotropic effects, as well as the ability to drop blood pressure. The latter is potentially happening to animals and humans due to nitric oxide being released. People often have neurotoxic effects such as convulsions, confusion, dizziness, headaches, numbness, paresthesia, etc. Severe effects might be paralysis of the limbs and heart failure. Adults might have severe issues but rarely die, it is often children most at risk of death.
Unlike some animals on this list, the Death Adder snake is only native to Australia and New Guinea. One might assume with a name like “death” adder, they might kill many humans or even attack a lot. This is ultimately not true, but they are relatively aggressive if you enter their environment. Their lightning-fast strike is notable, but you’re only going to see this if the snake feels threatened. Unlike some snakes, death adders lack hardly any fat and operate on mostly muscle.
This aids their strike speed, but also the power and pain of their bite. Naturally, they are one of the deadliest animals in Australia for reasons beyond this. Specifically, the venom they possess can kill people. When the snake bites, it averages 100mg of its neurotoxin in each bite. That can cause a healthy adult to die in just 6 hours. Thankfully, there is an antivenom on standby at Australian medical facilities. This is one major reason their death total is so low. Getting medical treatment immediately is recommended by experts.
While we might be discussing the Reef Stonefish in particular, all stonefish should be avoided if possible. The “reef” version is simply the most notable due to it being so widespread. This version of the species is also the most populous, so you’re more than likely going to run into it more than another. That said, stonefish are all over the world but this version of the species, in particular, loves the Australian region. Stonefish are the single most venomous fish species on the planet today.
They possess needle-like dorsal fins packed with venom. To hurt their prey, they essentially just ram into them to stick their spikes in. Different but effective neurotoxins are within their venom, which can be pretty painful. Pain lasts at least 24 hours but for many, it can take several days to fully stop as the venom works its way out of your system. Some people can die from their sting, specifically due to allergic reactions. While very few deaths occur, they can happen as soon as an hour after being stung. Therefore, it is recommended that you seek medical attention immediately.
The Blue-Ringed Octopus is absolutely beautiful. However, it has long been said that the more beautiful an animal is, the more likely it is to kill you. Almost like humans in a horror movie. Sorry, we saw the movie “Species” the other day and still have nightmares from it. That said, while this octopus is not exclusively in Australian waters, they are often found in the Pacific and Indian Oceans between Japan and Australia. Making them an Australian species worthy of note.
What makes the blue-ringed octopus one of the deadliest animals in Australia today? The potent venom it possesses. They have something known as “tetrodotoxin,” which they tend to use rarely. When they do, it’s enough to kill pretty much any species. Of course, human deaths are rare mostly due to the octopus being in the deep ocean. Humans do not tend to venture down that far very often. If the octopus did sting a person, it can kill them between 1 to 10 hours. There is no known antivenom for their version of tetrodotoxin either!
While Australia is known for its wide variety of spiders, very few are actually a major problem for people to worry about. Yet some, such as the Funnel-Web Spider, are among the deadliest animals in Australia today. They possess a Delta-Atracotoxin venom that is often referred to as δ-atracotoxin, which is an ion-channel inhibitor. It is a version of neurotoxin that is quite powerful and acts super quickly. For animals, it can cause a reaction within minutes and kill in less than 20.
For humans, things are a bit different. It targets our sodium ion channels and motor neurons, making them no longer function properly. This will then affect our motor function, but also our breathing. Interestingly, the venom will kill humans and other primates but it cannot kill any other mammal species. They bite roughly 30 to 40 people every year but only an estimated 14 have died from it. Humans can die within 15 minutes to an hour, which is why you need medical attention quickly if bitten.
The Great White Shark is the most feared shark species in the ocean. Yes, they too are not just found in Australia but can also be found all over the globe. Why do they rank high among the deadliest animals in Australia? This is mostly due to the numerous attacks on humans within this region. They might attack surfers, water skiers, scuba divers, etc. They are the shark species with the most unprovoked bites on humans. However, these are global statistics. With a large population worldwide compared to other sharks, they are bound to have higher numbers.
They do not tend to like eating us, funny enough. The human muscle and bone ratio is hard to digest for the great white shark, so they more often attack but do not kill and eat us. We’re ultimately too boney for them compared to fatty seals (which they love). Humans often seem to escape after their initial bite too. Yet they attack several people annually. Great Whites have been a vulnerable species, according to the Australian Government, since 1999. This is why the nation does not allow the random killing or “shark culling” of the great white shark. New Zealand and other nations also have conservation plans for them too.
Coastal Taipan Snakes are given their name mostly for sticking close to coastlines and being part of the taipan family of snakes, which isn’t really difficult. They do not truly kill many people per year because most know to steer clear of them if one just so happens to be nearby. All in all, they are the third most venomous snake on the planet today. Most of the time, they bite humans specifically out of defense rather than seek them out.
They are not highly aggressive but can be territorial. But if you steer clear of them. they’ll leave you alone too. The species know how powerful its venom is because they tend to warn us before striking. Usually, they freeze up after curling together, then lunge forward if they still feel threatened. The result is a deadly dose of venom every single bite. Their venom contains taicatoxin and neurotoxin at a 0.106mh potency that contains a 100% mortality rate for untreated bites. If medical treatment is sought out immediately, most humans survive their bite.
Australia is heavily known for its crocodiles. While saltwater crocs can be found in other places, freshwater versions can too. It is only in Australia, however, where you’ll see both. Australia’s freshwater version is not known as a man-eater, mostly due to the size of freshwater crocs. They will bite out of self-defense, however. Australia’s saltwater crocodile is the real killer to look out for. They do not mind attacking any species near them. Crocs have attacked lions, cheetahs, hippos, deer, and more.
While the crocs of Africa are bad, Australia’s crocodiles are heavily notable. This is mostly due to Australian conservationist and television host, Steve Irwin. Nicknamed the “Crocodile Hunter,” he helped us learn more about them and was very effective in several studies on the species. In total, roughly 1,000 people are killed by crocs annually. Many of these happen here, making them one of the deadliest animals in Australia today. However, the best thing to do if you see a croc is to simply run in the opposite direction. Try to not randomly go into marshes or places they are common, to begin with, too.
Australia certainly has a lot of snakes, and the Eastern Brown Snake is one of the most feared. This is ultimately due to their venom level, which ranks as the second-most of any snake on the planet. Australians see them quite a lot, which is why they are responsible for up to 60% of all snakebites in the nation every year. They tend to be pretty solitary, however. That’s probably why their yearly human bite count is not exactly massive.
People in the bush tend to be the most common to be bitten, as the eastern brown snake usually does not live around human beings. Yet encroachment on environments that these snakes hold has led to more interactions with them. The species is certainly deadly, and that’s due to what their venom is packed with. It has a potency of 5.0mg and filled with neurotoxin, hemotoxin, and mycotoxin. This is why it is capable of killing within 15 to 30 minutes, with a maximum of just 1 hour!
While Box Jellyfish can be seen in various places, they have been known for their heavy connection to the Australian region for many years. The species is responsible for more serious injuries to humans than sharks, sea snakes, and stingrays combined annually. Plus, they are known for killing up to 50 people per year. How do they accomplish so many injuries and even deaths each year? First, it’s due to traveling in packs where you won’t just see one jellyfish but often several.
Second, they rarely sting just once. When you are attacked with just one swipe of their venomous tentacles, they will send more in rapid succession. They contain what is known as “jellyfish venom,” which is mostly a combination of powerful neurotoxins. It can paralyze people, make it hard to breathe, cause heart problems, cause necrosis, shock, etc. That can make getting to safety after an attack quite hard. Depending on the severity, people can die from a sting or series of them anywhere from a few minutes to a few hours. It’s all dependent on the person ultimately.
The Inland Taipan Snake is the single most venomous snake on the planet today. Just one bite from this snake is enough to kill 100 full-grown men. The crazy part is that you’d think with so much packed in one bite, they’d be unable to offer lethal doses in other bites. However, the snake has an excellent recovery rate and can offer a severe strike several more times in a row without falling off of lethality.
The venom that the inland taipan possess is filled with neurotoxin, paradoxin, hemotoxin, oxytoxin, myotoxin, and som hyaluronidase enzymes. These add up to make the venom very deadly. Certainly enough to make this snake one of the deadliest animals in Australia. The venom is absorbed by the body quickly and results in human death anywhere between 5 minutes and just under 1 hour. There is an antivenom for it, but that’s if you’re lucky enough to get it in time.