Euastacus yanga, also known as the variable spiny cray, is a freshwater crayfish endemic to south eastern Australia.

[4] Their thorax has up to 20 spines on each side in one or two irregular rows although this is usually absent on smaller individuals (under 20 mm (0.79 in) OCL).

The propodus (fixed part of claw) has a well developed row of ventrolateral spines often extending to the tip of the finger, except in small specimens under 20 mm (0.79 in) OCL.

[4] The body is a deep brown-green or red-brown to brown on the back and fades to paler on the belly.

Their abdominal spines are yellow to pale orange though some larger specimens have a blue tinge.

The eggs are burgundy with white patches where the developing embryo was located and each female carries 43 to 164.

[1][2] Variable spiny cray are unsuitable for human consumption due to their small size.