Ferrets were small mammals, found on Earth. After the entire human population was regressed to cavemen, the Prime Minister of the United Kingdom was found up in a tree in Regent's Park eating a ferret. (COMIC: Hunters of the Burning Stone)
In circa 2000000, Lefty Lonnigan compared the Ricostans to ferrets, though Gloria Swannicker believed that they more closely resembled raccoons. (AUDIO: A Life of Crime)