Hehehe, I like this. And while I haven't seen sharks come out of showers I have seen crocodiles in swimming pools and I rather hope stonefish don't work out how to live out of water cause then I'd be quitly shitting myself As I live in the bush I regularly see Brown snakes and Black snakes as well as funnelweb spiders (and I always check shoes I've left outside before putting them on haha). Also, at my primary school when I was in grades 5/6 we did actually have a 'pet' huntsman spider called Harry who lived behind our classroom clock. Honestly (they like places like that).
But honestly, you'd be right. It's not that bad and you don't see creapy crawlies that often (and very rarely in the city). Plus, you'd miss all the brilliant stuff Australia's got, like it's beaches, friendly/funny people, the pubs, and lots more!
Blue ringed octopus (octopii?) are 12 to 20 cm long (about the size of your foot), and they are only 'blue ringed' when agitated - the rest of the time they are sand coloured. They have enough poison to kill 26 adults.
Box jellyfish have stingers up to 3 metres in length, and their sting is so painful that people have been known to try to kill themselves to stop it.
Crocodiles are not known to infest airports, though a group of kangaroos did manage to damage a F18 a few years ago in Darwin.
Sharks can be found in all countries (with sea-access), and arn't that scary, really - they usually only take a bite out of you, don't actually kill you. (the swimming back to shore with a large hole in you does that.)
Funnel web spiders... yeah their scary, but they only live around sydney (our biggest city), and since I don't live there, I don't care.
Taipans... Wikipedia lists the inland python as having the most toxic venom of any terrestrial snake species in the world. I may be confused, but I seem to remember reading that they were one of the few snakes that are actively aggressive, moving to attack people, rather than sliver away like most snakes.
Clock spiders are also rather fearsome. The ones you see in most pictures are only middle aged. They continue to grow as they age, and some huge ones have been found in old grandfather clocks. There are also rumours about clockmakers that go missing when sent to repair those large clocks mounted in buildings. I'm sure they're just romours though.