Erinaceidae contains two branches. One, the familiar hedgehogs, carries a dense coat of modified hairs hardened into spines. The other, the gymnures, never developed them and keeps ordinary fur. The greater moonrat is the largest gymnure, with long coarse black-and-white hair and a scaly, partly naked tail, and it is the only species in its genus.
Without armour, it relies on scent. Scent glands produce a strong odour, distinct from the musky smell of carnivorans and often described as ammonia or rotting onion, and the animal deposits it along its routes. The smell is strong enough that moonrats are commonly detected by nose before sight, and it appears to serve both territorial marking and deterrence.
The name invites two errors. The moonrat is not a rat and is not a rodent; it is an eulipotyphlan insectivore. The name's origin is not securely documented, and explanations tying it to moonlit activity are folk etymology rather than established fact. Basic ecology, including density and diet composition across seasons, remains thinly studied for such a large forest mammal.