Cilia (The Doctor on My Shoulder)

Princess Cilia was a member of the royal family of the Ulian Empire.

During the early 21st century, the Ulian Empire went to war with the Quintani. An anonymous assassination attempt was made against Cilia. In order to protect her, she was moved off-planet. Her ship became lost and she arrived in the Sol system. She hacked the Internet and learned of Father Christmas. She believed he would be able to help her return home, so she decided to hide on Earth. She used the Ulian shrinking technology to make heself six inches tall and hid on top of a Christmas tree, pretending to be an angel.

The Ulian robots who had been sent to protect her were able to track her down with the help of the Tenth Doctor. The Doctor was able to convince her to return home with the robots. (WC: The Doctor on My Shoulder)