Adult frill-necked lizards may grow up to one metre in total length. They often walk quadrupedally when on the ground. When frightened they begin to run on all-fours and then accelerate onto the hind-legs. In Australia, the frill-necked lizard is also known as the "bicycle lizard" because of this behaviour. Males are significantly larger than females both as juveniles and when mature. The frill of the Australian frilled dragon is used to scare off potential predators — as well as hissing and lunging. If this fails to ward off the threat, the lizard flees bipedally to a nearby tree where it climbs to the top and relies on camouflage to keep it hidden. Adult males fight for mates, displaying their frills and biting each other.
