Müller's rat has long, rough brown fur and a dark tail longer than its body. It is mainly nocturnal and ground-dwelling, but also climbs into low vegetation.
Its upperparts and flanks are brown, with long, rough fur and darker guard hairs. The underside is pale, and the dark-brown tail is longer than the head and body.
It is mainly nocturnal and mostly terrestrial, though it climbs into low vegetation. It eats both plant and animal matter, including insects, snails, and land crabs.
An extinction-risk assessment has not been added yet.