C. brevicornis is found in shrubs and trees of forest edges on Nosy Boraha (St. Marie) and Nnorther and eastern Madagascar. There is a subspecies of brevicornis (C. b. tsarafidyi) which is found only in the Tsarafidyi Forest. C. brevicornis is one of the species banned from export by CITES in 1995.

The most prominent feature of this chameleon is its large occipital lobes and the male's rostral adornment. The males reach a total length of about 13 inches (35 cm). The females are slightly smaller. The color consists of brown and grey tones and the males have a slightly ligher colored head. The rostrum can take on an orange to red coloration. There are also specimens that display more green coloration with blue legs and chin. There are some differences between the various subspecies and the nominate subspecies. The animals in Perinet differ in terms of the scalation of the dorsal crest. The females of Montagne de Ambre do not have a pronounced dorsal crest while the males do have such a crest. The animals from Ranomafana have blue legs and the rostral process is more strongly curved upward. Additionally there is a population, which becomes clearly larger from the nominate subspecies (Andreas Böhle, personal communication).

The temperature where this species lives varies throughout the year with daytime temperatures between 18 and 30 degrees Celsius, and nighttime temps as low as 8-15ºC or even lower. The annual rainfall is about 1000 mm, which gives a humidity around 50-60 % at daytime and around 80-90% at night.

For successful captive care the enclosure must be well planted and contain many climbing branches. The daytime temperature should be kept around 27ºC in the summer and around room-temperature in the winter. At night it is important that there is a significant temperature drop. This is a very sedentary chameleon but none-the-less they require a large enclosure. C. brevicornis is very agressive towards other specimens and, therefore, the sexes must be kept separately. The threat ritual is much like an elephants -it spreads out its "ears" (occipital lobes) and attacks with open mouth.

C. brevicornis is not a picky eater. All feeder insects are accepted as well as the occasional pinkie.

Breeding: Even though oviposition has been observed quite often, little is known about the incubation of the 10-30 eggs that are deposited approximately 40 days after mating but they reportedly do better at room temperature (Andreas Böhle, personal communication).