Australia is home to some of the world's deadliest snakes. There are seven families of snakes that can be found Down Under, most of which belong to the venomous family Elapidae.  The fierce snake, or taipan, is believed to have the most toxic venom produced by a land snake in the world. Fortunately, they only live in sparsely populated areas of southwest Queensland and Southern Australia. Taipans grow to over two and a half metres long.  There has been an anti-venom available for the taipan's venom since 1950, but before that a bite was almost always fatal.  Overall, there are six species of snakes in Australia that are dangerous to humans. Following the taipan in order of deadliness are: the tiger snake, death adder, the king brown snake, brown snakes and copperhead snakes. Australia is also home to about 15 species of pythons. The smallest is the half-metre long dwarf python of Western Australia. The longest is the scrub python of Queensland, which grows up to five metres in length.

There are two species of crocodile in Australia - the saltwater and the freshwater.  Saltwater crocodiles are among the world's largest crocodiles, with males often reaching an average length of five metres. But some specimens have been known to reach lengths of six to eight metres. Females grow up to 2.5 metres long. Saltwater crocodiles live in rivers, estuaries and coastal waters in northern Australia and eat a wide variety of prey. The young ones stick to insects, amphibians, small reptiles and fish. But adults target bigger prey like turtles, goanna lizards, snakes, shore and wading birds, wild boar, monkeys and even domestic livestock like cattle and buffalo. And they have been known to attack humans.  Freshwater crocodiles, on the other hand, aren't usually dangerous to people. They live in permanent freshwater streams, rivers and large water holes in northern Australia. Freshwater crocodiles aren't as big as their saltwater cousins either, reaching a maximum length of three metres.