, Malaysia, showing the deeper colour of the underparts of individuals from small islands in this region The black giant squirrel is one of the largest species of squirrel in the world. On average, an adult black giant squirrel weighs around , has a head–and–body length of , and the tail is long. The
subspecies R. b. condorensis of Vietnam's
Côn Sơn Island averages only in head–and–body length and the tail , but otherwise it resembles the typical subspecies. This species is typically distinctly bicoloured with dark upperparts and pale underparts. The back, top of the head, ears and bushy tail are deep brown to black and the underparts are light
buff-coloured. In
Sumatra,
Java and
Bali the hairs of the back and tail are light-tipped, making these sections appear relatively pale (however, the upperparts, especially the thighs and shoulders, are still distinctly darker than the underparts). On small islands off Myanmar and in the
Strait of Malacca, the black giant squirrel has orange to reddish-yellowish underparts. ==Habitat==