The veiled chameleon (Chamaeleo calyptratus) is a species of chameleon (family Chamaeleonidae) native to the Arabian Peninsula in Yemen and Saudi Arabia. Other common names include cone-head chameleon and Yemen chameleon.
The male is 43 to 61 cm (17 to 24 in) long from the snout to the tip of the tail. The female is shorter, no more than about 35 cm (14 in), but it has a thicker body. Both sexes have a casque on the head which grows larger as the chameleon matures, reaching about 5 cm (2.0 in) in the largest adults. Newly hatched young are pastel green in color and develop stripes as they grow. Adult females are green with white, orange, yellow, or tan mottling. Adult males are brighter with more defined bands of yellow or blue and some mottling.
Coloration can be affected by several factors, including social status. In experimental conditions, young veiled chameleons reared in isolation are darker and duller in color than those raised with other individuals. Females change color across their reproductive cycles. Chameleons also tend to change to a much darker color when stressed.