All have a spike behind each eye. Extremely strong claws for digging. This genus used to be included with the Gonocephalus but sorted out. Slight lateral compression. Strong orbital ridges.
Most species have a nuchal and dorsal crest which runs down the back similar to the water dragons.
Legs and toes are long, heavily clawed for climbing trees. Mouth is quite large, and quite capable of inflicting a painful bite in the bigger species. All are slightly laterally compressed with strong bony ridges on face running from the rostrum, back between the eyes to the back of the head. Males have dewlaps. Usually found on the ground or only a short distance above the ground in low bushes.