Moderately large brown-grey lizard with darker splotches closely resembling the tree bark. Its most distinctive feature is the Elizabethan-like ruff or frill that opens for courtship displays, territorial defense, and to frighten would-be predators. Males are significantly larger than females.

The frilled lizard is one of Australia's most iconic animals due to the unique way it reacts to perceived threats. The lizard usually hides in trees, using the foliage as camouflage while hunting its favorite insect meals and avoiding predators. When it feels threatened, it surprises its foe by extending the frill of thin skin around its neck in an attempt to look much larger and more fearsome. If this tactic doesn't scare off the threat, the lizard will stand up and charge in a final attempt to frighten its foe before turning tail and escaping into the treetops.