Actually, not everything in Australia can kill you. Some of the sheep are harmless.
Seriously, though, I don't travel around Australia much. (I work in healthcare, so that doesn't leave me a lot of time off).
So, I haven't seen many of those tiny horrors.
In about 30 years of living in Australia, I was bitten by two spiders and one wasp.
I guess that makes me the luckiest, the most cautious, or the least adventurous guy in Australia (or all three).
Regardless, I'm not keen to go anywhere near those lethal things.
The number one thing on that list is the cassowary, a bad-tempered fiend from Hades that can run as fast as a horse and stab you with a five-inch, dagger-like claw.
Don't make those things angry. They'll mess you up good.
I also noticed the saltwater crocodiles listed there. Yes, the salties (as they're known here in Australia, or 'crocs') are definitely killers, no doubt about it. As a race, they've survived since the days of the dinosaurs, which should command a healthy respect in anyone's book.
Want some fun? Google "NT News crocodile headlines", and you'll see the sort of silly things that people in the NT (Northern Territory) get up to with crocs. The NT is hot most of the year, and there are crocodiles living in swamps and marshlands there. (Think the Netherglades in Florida, and you'll get the right idea). Just be warned: some of the headlines in the NT News are NSFW.
Some instances include "Surf's up, nude" (about a "daredevil" who hunted crocodiles while in his birthday suit), or "What a croc head" (about someone who went swimming with crocodiles).
Some people are just plain crazy.