Tiger (In the Forest of the Night)
From Tardis Wiki, the free Doctor Who reference
In the 2010s, a tiger was kept in London Zoo.
When a forest grew mysteriously around Earth, the tiger escaped. Whilst exploring its new habitat it came across some wolves that were scaring Clara Oswald, Maebh Arden and the Twelfth Doctor. The Doctor thought his plan to be a three-headed, six-legged monster had worked, but then Clara asked the question: "What are wolves frightened of?" The tiger then emerged but was scared away by Danny Pink's use of a torch; directing light into the tiger's eyes. (TV: In the Forest of the Night)