Scientific name: Endoxyla leucomochla (Turner, 1915)

Witchetty grubs live in tunnels in the ground where they feed on sap from the roots of two species of Acacia, commomly known as Wichetty Bush and Small Cooba. The caterpillar grows to an approximate length of about 7cm and pupates inside its tunnel. The adult is a large grey wood moth with finely mottled wings and a wingspan of about 16cms. The adult, a wood moth, posesses degenerate mouthparts and relies completely on the nourishment it obtained as a caterpillar to meet its energy requirements.

http://bugs.bio.usyd.edu.au/Entomology/importance/imagePages/wijuti_grub.html