Closest is Charaxes Sempronius as far as I can tell, but nothing mentions the colour I can see on the head with that one. I've included a picture of the leaves of the plant in case that's relevant. It was beside the rainforest gully.
Looks to be approaching the third instar stage. Refer BCSA (Butterfly Conservation South Australia Inc) website page: https://sabutterflies.org.au/nymp/sempronius_gallery.html#larvae . Nice to see part of the silken bed the larva has laid in image 2.