A small chameleon native to the rain and dry forests of northern Madagascar near Joffreville (Montagne d'Ambre) where it inhabits trees, bushes of dry forests or gardens. Day time temperatures generally range from the 75-85ºF with a night time drop of 10-15ºF. Humidity is high, around 70% during the day and 90% at night. Total length or 6-7 inches. Females are slightly smaller. F. petteri was formerly considered a subspecies of F. willsii.

The small head bears a low casque lacking occipital lobes. In the male, two laterally compressed rostral processes extend from the the rostral crests. Enlarged scales cover these rostral processes. Body scalation is largely homogeneous but a low dorsal crest of conical scales is apparent. Gular and ventral crests are absent.

The basic coloration is green with white, and less commonly, yellow, red, and blue markings. "Breeding males develop cross stripes and females change to lime yellow with a rich red color on top of their heads, just between the rostral crests." (Necas, 1999, p. 230). A courting male develops blue striping. A non-receptive female will respond by darkening and may attack the male. Females lack the rostral processes and males exhibit a boadened tail base and hemipenal bulge.

Individual caging is mandatory for this highly active and aggressive species. Frequent mistings are necessary as animals lick droplets from plant leaves. Following mating, females become increasingly aggressive and lay after about 30 days. Incubation at 73-75ºF results in incubation after approximately 240 days.