The weasel sportive lemur (Lepilemur mustelinus), also known as the greater sportive lemur, weasel lemur, or greater weasel lemur, is a species of lemur native to northeastern Madagascar. Its habitat includes rainforests and tropical rainforests. Its dorsal side is a reddish-brown colour, and greyish brown ventrally. Its colour darkens towards the tip of its tail. Individuals weigh from 0.8to It has long, soft fur. Its body length is approximately 22– and a tail length of 23–.
The weasel sportive lemur is predominantly a leaf-eater, although it supplements its diet with fruits and flowers. It is an arboreal species, and travels through the trees by leaping. As with other leaping primates, it has stereoscopic vision that enables it to determine distances precisely. Groups consist solely of a mother and its offspring; the males are solitary, and are very territorial. Each weasel sportive lemur occupies a territory of to 1‑ acres (1500–5000 m2). Like some other lemurs, they are nocturnal.