The easiest way to find out what a degu looks like is by looking at this video.
         Chris's degus Buffy and Willow after their dust bath
           (2 min 9 s - 35 MB)
         A video from Czech TV (with Marketa and Frank Traksl)
              (3 min 24 s - 4,2 MB)
         Jana's little degu Zofie (37 s - 2,1 MB)
         The video with Bobes's degu Karel (30 s - 2,3 MB)
         Petr's degu, Dareba (2 min 37 s - 1,8 MB)
         Another video of Dareba (2 min 15 s - 1,6 MB)
For those whose Internet connection is too slow, I will also try to describe how the degus' look.

Degu (Octodon degu) is a tweed brown (other colours are a rare exception), long-tailed rodent. Their tail makes up one third to two third of the whole body length and has brush-like hair at its end. When walking, they wear their tail up with pride and when climbing they wave with it to keep their balance.

They look a little like gerbils, only bigger. Some people find them similar to chinchillas, with whom they are related. Behaviour-like, they act a lot like squirrels and that is the reason why they are called "Chilean squirrel".

The degu is as big as a small guinea pig. Remember this when you are buying a degu. People buy degus when they are as small as hamsters (when they are very young). They buy a small nest-box, small running wheel and a small cage. Then, after a few months people are surprised at how much the degu has grown and the fact that everything they bought is now too small for the animal.

The hair is tweed brown coloured, the tummy has a cream colour and they have lighter circles around the eyes. They have long whiskers, and their quite big ears are dominant. The hind legs are shorter than their forelimbs. Each has five hair-covered fingers that degus often nibble on, so their claws do not grow too long. Therefore you don't have to cut the, like you do with dogs. Another thing of interest is that the teeth of degus are yellow or orange coloured. Degus' teeth become orange a couple of weeks after their birth because of the reaction of chlorophyll from green plants with degus' saliva - this reaction also makes the degus' saliva orange. So the colour of teeth also depends partially on what they eat.