Anolis ferreus, the Morne Constant anole, also known as the Marie Gallant sail-tailed anole, is a species of anole lizard that is endemic to the island of Marie-Galante, which is part of Guadeloupe in the Caribbean Lesser Antilles. It has been recorded as an escapee in Fort Myers, Florida, but does not appear to have become established. Males can reach 11.9 cm (4.7 in) in snout-to-vent length, while females are significantly smaller, at 6.5 cm (2.6 in). It has a yellow-green dorsal surface, and a blue-gray head with yellow around the eye. Males have prominent tail crests.