The thick-tailed galago, Otolemur crassicaudatus , is the largest galago species. Head and body length ranges from 297 to 373 mm, and tail length, from 415 to 473 mm.
Body size is sexually dimorphic with males being significantly larger than females.
The coloration of the fur is silvery brown to gray with the underside usually lighter in color. The fur is dense, woolly, quite long, wavy, and usually described as without luster. The ears of O. crassicaudatus are large and can be moved independently of each other backwards and towards the base of the ear. They often furl and unfurl their ears giving them a quizzical expression. The eyes are forward pointing and large.