The short-tailed chinchilla is a compact rodent with a small, rounded head and a short tail. Its body is covered in dense fur that is typically gray, but may also be black, white, or brown. On average, short-tailed chinchillas are around 10 inches (25 cm) in length, not including the tail, which is typically 2-3 inches (5-8 cm) in length. They weigh between 1-2 pounds (450-900 grams). Despite their small size, short-tailed chinchillas have powerful back legs that allow them to jump several feet in the air.