The beautiful black giant squirrel is one of the largest squirrels in the world. It inhabits tall primary forest and generally remains high in the canopy, but at times may be found at lower levels when feeding. It is largely solitary in habits and extremely shy, rarely coming to ground. It can confidently make huge leaps from branch to branch in the high canopy.

Its upperparts and tail are jet black, but the cheeks, chest, front of the forelimbs and underparts are cream or orange. The tail is long and dorso-ventrally flattened.

Fruits, seeds and young leaves make up its diet, supplemented by occasional insects and sometimes birds' eggs. It builds a large, spherical nest of leaves and twigs.

The species once ranged extensively from Nepal and Assam through Burma, Indochina and Thailand to Peninsular Malaysia, Sumatra, Java and Bali. Its numbers have declined with the large-scale clearance of primary forest. It is absent from Singapore.