D. arboreus has a somewhat marmot-like or guinea pig-like appearance. Long, soft, grey-brown fur covers the body, while the underside is paler. Hairs are lighter near their tips. The ears have a fringe of white hair. A dorsal gland is conspicuous in the middle of the back as it is ringed by creamy white hairs (total length 23-30 mm). D. arboreus lacks an obvious external tail.
These animals weigh about 2.27 kg on average, and have an average length of 520 mm. The BMR for this species is reported to be somewhat low for its size.
Four sub-species are recognized: D. arboreus stuhlmanni, D. arboreus crawshayi, D. arboreus ruwenzorii, and D. arboreus aldofi-friederici. Ranges overlap, although some habitat differentiation has been reported where the sub-species co-occur.
Average mass: 2.27 kg.
Average length: 520 mm.
Sexual Dimorphism: male larger
Average mass: 3000 g.