Clara Oswin Oswald's TARDIS key

Clara Oswin Oswald briefly held possession of a TARDIS key.

History
Shortly after encountering the Eleventh Doctor in December 1892, Clara was given a key by him in what he described as him "giving in." Immediately after, the Ice Governess broke into the Doctor's TARDIS and grabbed Clara, causing her to drop the key. A struggle ensued which resulted in both the Governess and Clara falling over the edge of the cloud the TARDIS was situated on, shattering the Governess while gravely injuring Clara. The Doctor did, however, return the key to Clara just prior to her death. (TV: The Snowmen)