Australians are proud of their wildlife, which is not only the oddest in the world, but also the most dangerous. That's not to say that it's a dangerous country, because most animals do not go out of their way to attack people. You just don't want to take any chances by provoking the native species.
There are many species of box jellyfish native to Australia, the Philippines, and other tropical areas. Some are not dangerous to humans, but one species, Chironex fleckeri, is the world's most venomous animal. The sting from this particular species can cause death in minutes! If stung by a box jellyfish, apply vinegar before removing the tentacles, or it will inject more venom. That's why Australians take vinegar along when swimming at some beaches during jellyfish season.
The Guiness Book of World Records lists the cassowary as the world's most dangerous bird. They live in the tropical areas of New Guinea and northern Australia, where it is an endangered species. Cassowaries are bad tempered birds that can grow to 6 feet tall. They are strong and swift and attack with razor-sharp claws. Although the last cassowary-related death was in 1926, many people have been badly injured by these birds. Image by Paul IJsendoorn.
Barrier Reef cone shells include 80 species found in Australia. They are pretty shellfish with sharp teeth that can penetrate clothing. Their venom is a neurotoxin that can kill a human, and there is no antivenin. Medical facilities can help a victim breathe until the toxin is cleared from the body.
The world's most venomous octopus is, of course, found in the waters off Australia (as well as Asian seas, as far north as Japan). The blue-ringed octopus is yellow with black and bright blue rings on its surface. It's a tiny creature, about the size of a golf ball, but contains a neurotoxin powerful enough to kill humans. There is no antidote, but victims who reach medical help often recover if breathing is assisted until the venom dissipates. Image by Jens Petersen.
The inland taipan, also known as the fierce snake, is the most venomous snake in the world. It is found in the dry regions of central Australia. The taipan's venom is toxic enough to kill 100 humans with the dose found in a single bite. This snake lives on mice and small rodents and is not aggressive towards humans. People have been bitten when a taipan feels threatened. No human deaths have been recorded from the taipan's bite, thanks to treatment with taipan antivenin produced by the Australian Reptile Park. Australia is home to many other species of highly venomous snakes. Image by AllenMcC.
There are many different kinds of spiders in Australia. The Sydney funnel-web spider (Atrax robustus) has a reputation for its nasty venom. These spiders act aggressively when approached. The male spider's venom is five times as toxic as the female's. A bite will lead to muscle spasms, shock, and brain damage, but is easily treated with antivenin. The redback spider is another Australian spider to watch out for. It resembles (and is related to) the black widow spider.
Since the dinosaurs are gone, the saltwater crocodile is the world's largest reptile. The average croc is about 15 feet long, but they can grow to over 20 feet! Australians call them "salties". Death by crocodile is rare; there are only a couple of fatalities every year in Australia. That's more than enough.
Scorpion fish that live near the Australian coasts are the world's most poisonous fish. They have glands containing neurotoxins at the base of their fins, which they use only in defense. Scorpion fish are found in tropical waters all over the world, but are most concentrated in Australia. They are small and approachable, but if you step on one, you'll need to seek immediate medical treatment. They are also edible, and considered to be a delicacy. Image by CW Ye.
The drop bear (Phascolarctos carnivorous) is a truly scary animal. A marsupial native to Australia, it is a vicious carnivore that attacks its prey by hiding high in a tree and dropping onto unsuspecting bystanders. Photos of a drop bear show a startling resemblance to a koala, which is how the sneaky beasts fool you into standing under their trees. See the drop bear in action in this video. The most important thing to remember about drop bears is that they only bite tourists.