The guinea pig (Cavia porcellus), also commonly called the Cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not pigs, nor do they come from Guinea.
In Western societies, the guinea pig has enjoyed widespread popularity as a household pet since its introduction by European traders in the 16th century. Their docile nature, their responsiveness to handling and feeding, and the relative ease of caring for them, continue to make the guinea pig a popular pet. Organizations devoted to competitive breeding of guinea pigs have been formed worldwide, and many specialized breeds of guinea pig, with varying coat colors and compositions, are cultivated by breeders.
Here is a cute gallery of the Guinea Pig Olympics. Various sports shown are archery, fencing, swimming, weight lifting, boxing, table tennis and others.