 The origin of the modern fancy rat begins with the rat @-@ catchers of the 18th and 19th centuries who trapped rats throughout Europe . These rat @-@ catchers would then either kill the rats , or , more likely , sell the rats to be used in blood sport . Rat @-@ baiting was a popular sport until the beginning of the 20th century . It involved filling a pit with several rats and then placing bets on how long it would take a terrier to kill them all . It is believed that both rat @-@ catchers and sportsmen began to keep certain , odd @-@ colored rats during the height of the sport , eventually breeding them and then selling them as pets . The two men thought to have formed the basis of rat fancy are Jack Black , rat @-@ catcher to Queen Victoria , and Jimmy Shaw , manager of one of the largest sporting public houses in London . These two men are responsible for beginning many of the color varieties present today . Black , specifically , was known for taming the " prettier " rats of unusual color , decorating them with ribbons , and selling them as pets . 
