Kangaroo
From Tardis Wiki, the free Doctor Who reference
Kangaroos were mammals common to Australia. On at least one adventure with the Eleventh Doctor, Abigail Pettigrew went to Uluru and was photographed in front of a kangaroo crossing sign. (TV: A Christmas Carol)
Immediately after regeneration, the Seventh Doctor's brain was addled, and he unwittingly altered several common metaphors. He claimed that Melanie Bush had the "mind of a kangaroo", before she reminded him that the people with great memories were said to have the "mind of an elephant". (TV: Time and the Rani)