There is a picture in Caterpillars, Moths and their Plants of southern Australia by Peter McQuillan, Jan Forrest, David Keane & Roger Grund 2019 of a similar looking caterpillar - Nygmia edwardsii Mistletoe Browntail Moth. I expect this fabulous looking creature is another species or a related genus. The plant in this picture looks like a wattle ?? McQuillan et al also mentions similar moth Euproctis marginalis larvae are found on Eucalyptus microcarpa