This is the sole species of genus Moloch. The thorny devil grows up to 20 cm (8.0 in) in length, and it can live for up to 20 years. Most of these lizards are coloured in camouflaging shades of desert browns and tans. These colours change from pale colours during warm weather and to darker colours during cold weather. These animals are covered entirely with conical spines that are mostly uncalcified