Description: A large lizard, up to 40 cm in total length; 10-12 cm snout-vent length. Dorsum tan or grey, with or without irregular dark crossbar markings; markings sometimes reduced to irregular mottling. Head large and bony. A prominent crest begins at the neck and extends down the body. Crest absent in hatchlings. Scales strongly keeled except those on top of head. 3-5 dark-coloured streaks fan out from each eye. Underside greyish. Tail long, whip-like, more than twice the body length; banded with brown. Adult males have a gular pouch; black and red when in full colour. Females more drab in coloration.
Habits and habitat: A sun-loving lizard. Most of ten seen basking on shrubs, sometimes on wall or foraging on the ground. Is most characteristic of dry, open shrubland and edges of cultivated fields. Scarce in dense forest; possibly absent in mountain grassland. Can change body coloration to a certain degree. Is capable of rotating each eye independently. When approached, will usually cock an eye at the intruder and eventually scurry up a tree or into a bush if further danger threatens. If caught, will thrash and attempt to bite. Sleeps on vegetation at night.
Diet: In captivity feeds on crickets, cicadas, grasshoppers and beetles. Will lap up water sprinkled on leaves.
Reproduction: Breeds in spring and lays eggs in the soil in summer. During courtship display males turn their extended gular pouch black-red, and the head and forebody crimson. Display also includes the male bobbing his head. He may bite the female during pairing, but causes no injury. Hatchlings some 6 cm in total length.
Distribution: Common throughout the territory, including all major islands. Recorded up to 920 m. Very widely distributed from southern Iran eastward to extreme southern China, and southward to Sumatra (Indonesia).
Diagnostic features: Large, triangular head; pointed snout; chin and flanks striped; a crest on neck; scales keeled; long whip-like tail; long clawed digits.