Country Ausfag here.
Yes and no.
By and large 99% of them just want to be left the fuck alone and will only really arc up when some cunt pisses them off, but if they do get angry then they can fuck you up.
But almost always they're not interested in that, with some notable exceptions. Breeding season Sydney funnel webs get pretty angry and they roam which means you can find them on the back lawn or (occasionally) in the house. Cassowaries are rare, and you have to be pretty unlucky to find one in the mood for ruining your day. There is a couple of different snakes that'll chase you if they're in the mood, but again you have to be pretty unlucky.
As far as the flora and fauna are concerned, the price of living in Australia is eternal vigilance. Living with the wildlife is easy provided you take precautions and know what you are dealing with if one of them does get pissed off that his great new home turns out to be your gumboot.
tl;dr: If you go sticking your dick into stupid places without checking that happens to have an animal that does not take kindly to your presence, it will hurt you. What a fucking shocker.