I strongly suspect this bug to be a species of Riptortis, possibly R. serripes. It is standing on an unknown exotic pot plant. The body is long, narrow and waisted (photo 3), in mostly brown and black, with the black merging to a fawn colour going further forward, (photos 2, 3 & 5). The legs and antennae are long and mostly black with 1-3 narrow bands of white (photos 1 & 2). It has a lateral ridge spanning its thorax, ending each side in an upward facing sharp spike (photos 5, 4 & 1). There appear to be 4-5 dark brown spots on the sides of it abdomen.
Noliphus annulipes, in family Alydidae https://bie.ala.org.au/species/https://biodiversity.org.au/afd/taxa/64aaacdd-6da0-46da-b68d-13baf76d407d#overview