The large bamboo rat, Sumatran rat, or Indomalayan rat (Rhizomys sumatrensis) is a species of rodent in the family Spalacidae found in Cambodia, China, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. It is one of four species of bamboo rat. Individuals can reach lengths of nearly 50cm with a 20cm tail, and weigh up to 4 kilograms (8.8lb).