It is the largest rodent in Chile and can reach 7 kg. Nocturnal and crepuscular herbivorous. Its feeds on grasses, guatona grass, rushes and cattails. It inhabits ponds, lakes, rivers,
estuaries and wetlands with cattails, albatros or similar vegetables. It has arched body and short legs, very thick and silky fu,r as well as a stiff brown fu,r ranging from pale to very dark brown with blackish yellow overtones.