The tail is large, flat and covered with rings of spines, from which it takes its colloquial name. The dorsal scales are imbricate, and their size is noticeably smaller than the ventral scales. The colouration of this lizard is highly variable. The basal colour is grey, but red, orange, green and yellow specimens are also encountered. The sides of the body are blackish with bluish 'reflections' or scintillating flashes of red or orange.
Juveniles are typically plain grey with brown or darker spots.
Unfortunately, there are no reliable external indicators from which the sex of a specimen may be determined. Our mission to the Ouarzazate region of Morocco was inspired by concern at frequent sightings of crudely stuffed examples of these most remarkable lizards in souvenir shops and as decorations on traditional herbal medicine stalls. From the observed level of exploitation, it was obvious that, like the tortoise Testudo graeca graeca, and the chameleon Chameleo chameleon, this is a species which is potentially threatened by trade. We specifically wished to gather information on local collectors and trade levels, and, insofar as limited time allowed, on the habitats and diet of this species in Morocco. Our route took us via the ancient walled city of Taroudannt, situated in the fertile Souss valley, through the stark and arid mountains of the Anti-Atlas.