10 Doctor Who Characters Who Rejected The Doctor

10. Osgood

If you had to compile a small list of NuWho side characters who would make excellent full-time companions, then Osgood would almost certainly make the cut.

A UNIT scientist with a deep admiration for the Doctor, her intelligence would definitely come in handy when battling Daleks and space insects and sentient shadows, and plus - unlike so many of the Doctor's other companions - she would know exactly the sort of peril to expect if she were to live the TARDIS lifestyle.

Also, she dresses like the Doctor. That's an automatic win right there.

Sadly, Osgood did not become a full-time companion, but she was asked, with the Twelfth Doctor inviting her to join him at the end of Series 9's The Zygon Inversion. However, Osgood declined, reasoning that it was better for her to remain as a protector of Earth. Definitely the right call, considering how many deadly aliens just seem to gravitate towards our planet.