Wattle Cup Caterpillar (Calcarifera ordinata)

This amazing-looking creature is the larval form of a rather unremarkable brown Cup moth, but as a caterpillar it is highly toxic.  It lives, with all the other toxic, poisonous, and venomous creatures, in Australia.

Photo credit to Nadia302, via The Twenty Most Toxic Caterpillars.   Another great photo here.