The Goliath stick insect (Eurycnema goliath) is the second largest stick insect (after the Titan stick insect) in Australia, and though not as long, the insect has a heavier, sturdier build. The first instar of a nymph is small, brown, and ant-like, without wings, however the adult insects are green and yellow, though colors can slightly vary, are very large, and have wings.
Both sexes of the Goliath stick insect are apple green with hints of gold, purple, red and yellow. Colourful patterns on the underside of the wings of Goliaths are used as a defence tactic in order to ward off predators. The females can reach lengths of up to 20 cm. The eggs of the Goliath stick insect look like seeds, so that common ants may take them underground, allowing them to hatch in safety. Males are smaller, slimmer, and darker in color to females. While both sexes have wings, only the lightweight males can fly, as the females have a large, heavy abdomen which gives them limited, if any flight.
The Goliath stick insect can be found throughout Australia except for Victoria. Goliath stick insects are extremely hard to find due to their camouflage and tendency to hide in tree tops. They can be found mostly in Eucalyptus trees, or small native flowers such as acacias.