The physical appearance of an aye-aye can be described as a strange-looking, nocturnal primate with prominent ears, large eyes, a long thin middle finger used for tapping and prying open food, bushy tail, shaggy black fur, and a bony face with large incisors. They are about the size of a small cat, measuring around 14-17 inches (36-44 cm) in length, and weighing about 2-4 pounds (0.9-2 kg).