Hamster
From Tardis Wiki, the free Doctor Who reference
Hamsters were Earth mammals. In her youth, Ace was the "hamster monitor" in the classroom run by Miss Marshall. (PROSE: Legacy) The Fourth Doctor once reproached K9 for his slow progress in cutting through a wall with his laser by saying that "a hamster with a blunt penknife" could do it more quickly. (TV: The Androids of Tara)