Ferret
Ferrets were small mammals, found on Earth. (COMIC: Hunters of the Burning Stone, AUDIO: A Life of Crime, etc.)
Charles, the leader of SIGNET, owned a puppet ferret called Mr Fizzle. (PROSE: Hervoken Halloween [+]Loading...["Hervoken Halloween (short story)"])
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)
Timbo, a presenter for Max Warp, had the nickname of Ferret, referring to the animal. (AUDIO: Max Warp)
The Seventh Doctor used to know someone who put ferrets down his trousers. (AUDIO: An Alien Werewolf in London)