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. To protect her, she was moved off-planet. Her ship was lost and she arrived in the Sol system. She hacked the Internet and learned of Father Christmas. She believed he would 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 which had been sent to protect her tracked her down with the Tenth Doctor's help. The Doctor convinced her to return home with the robots. (WC: The Doctor on My Shoulder)