Eulemur macaco males and females having different coloring. Males are a uniform black, but in sunlight their fur can have a reddish-brown to dark brown sheen. Tufts of hair are visible in their ears. Females have a brown to blackish-brown back, brownish limbs, and a light brown to pale gray belly. The head and muzzle are dark gray, and females have long tufts of white hair in their ears. Both sexes have a very long, bushy tail.

Lemuridae is a family of prosimians, a suborder of primates, endemic to Madagascar. In ancient Rome, the word "lemur" meant ghost (or spirit). The name lemur was given to this group of animals because they are primarily nocturnal. These animals range in size from a mouse to a small dog.