(There are so many cannon characters and I don't know them all.)
If you fancy playing a cannon character, please comment which person down below and I shall then post upon this page which characters are taken in order to avoid confusion.
Cannon characters include the different Doctor regenerations, the companions and such; quite simple to understand. Also, make sure you have a thorough understanding in the way your character behaves and acts.

Tenth Doctor is claimed! He's taken. I'm so sorry...
Rose Tyler is Taken also. I'm sorry.