Porcupines were mammals native to Earth. Rose Tyler once saw a nature programme on television about porcupines and learned they were irresistibly attracted to salt. She used this information against the Quevvils, a porcupine-like species. (PROSE: Winner Takes All) On another occasion, the Ninth Doctor offered Rose the chance to see the "first porcupines" from Earth's Oligocene era, but she preferred 1960s London. (COMIC: The Love Invasion)
In 430 BC, whilst on a mission for the Braxiatel Collection near Delphi, Bernice Summerfield's grasp of ancient Greek failed her and she used the word porcupine instead of the word gentlemen. This caused some confusion amongst the men she was trying to address. (AUDIO: The Oracle of Delphi)
