This beetle is Archetypus frenchi (family Cerambycidae; subfamily Prioninae). It measures around 50 mm and is rather formidable.
These jaws are not for predation but for chewing into wood for egg laying and for defense. Such large beetles are a potential food source for many reptiles, amphibians, birds and mammals.
This is another prionine cerambycid. It is even larger than Archetypus. Curiously with their great size, appearance and appeal as specimens for a collection, Australian prionines are in need of revisionary studies. About 1200 Australian species have been described but there are many undescribed species waiting in line for taxonomists to name them.
Many cerambycids can deliver a painful bite. They have very good eyesight and use it effectively.Thanks to Jack Hasenpusch for the identification of Archetypus.