The Parson's chameleon is a very large species of chameleon that is endemic to isolated pockets of humid primary forest in eastern and northern Madagascar. It is listed on CITES Appendix II, meaning that trade in this species is regulated. As with the majority of chameleon species from Madagascar, it is illegal to import Parson's chameleons from their native country.
Among the largest chameleons in the world , males have ridges running from above the eyes to the nose forming two warty horns. There are two recognized subspecies: The widespread ''Calumma p. parsonii'' reaches up to 68 cm in length and has no dorsal crest. ''Calumma p. cristifer'' from near Andasibe reaches 47 cm and has a small dorsal crest. Several colour variants are known within the range typically included in the nominate subspecies, but it is unclear if they are best considered morphs or different subspecies . This includes "orange eye" ''aka'' "white-lipped" where the male is relatively small and mainly green or turquoise but with yellow or orange eyelids, "yellow lip" where the male is somewhat larger and mainly green or turquoise, but with a yellow edge to the mouth, "yellow giant" where the male is very large and overall yellowish , and "green giant" where the male is overall green. Males of ''C. p. cristifer'' are overall green or turquoise. Females of all are smaller than the males and overall greenish, yellowish or brownish .
In captivity, females lay up to 50 eggs per clutch which can take well over a year to hatch. Females only reproduce once every two years. When the babies are hatched they are on their own immediately.
