Smallest veiled chameleon subspecies

The veiled or cone-headed chameleon's large, nominate subspecies, Chamaeleo calyptratus calyptratus, native to the Arabian Peninsula, measures up to 60 cm in adult males, and is the most common chameleon in the pet trade. Conversely, adult specimens of its smallest subspecies, the Yemen veiled chameleon C. c. calcarifer, confined to Yemen and immediately adjacent Saudi Arabia, can measure as little as 43 cm, and is less commonly seen in the pet trade. Also, its head-borne casque or cone is proportionately shorter in both sexes than that of the nominate subspecies.

This species' distinctive head casque, up to 10 cm high in adult males of the nominate subspecies (it is much shorter in females of both subspecies), apparently has more than one function. By increasing the chameleon's overall size, it makes it look more daunting and therefore less attractive to potential predators. It also serves as a water-condensation site, with its moveable rear lobes channeling water in the form of condensation or dew down to the corners of the chameleon's mouth, which it then drinks. This also may assist in attracting female attention when the male is performing its characteristic head-rolling courtship displays.