The White Queen

 was a fictional character in a book written by C. S. Lewis encountered by also-fictional versions of the Eleventh Doctor, Amy Pond and Rory Williams.

History
After being transported into the book containing the Queen, the Doctor, Amy and Rory found her as a statue which soon came to life, chasing them. They escaped, but she followed them, managing to reach their destination years before them. The trio later arrived to find that the Queen had enslaved the natives and made it "always winter". She temporarily killed the Doctor before Amy pulled her back into the book she came from.

Abilities
She could generate lethal green energy blasts, which she shot out her hands. This was used to kill the Doctor.

While flying through "the space between worlds", she seemed to resemble a monstrous old woman in dark clothes. Finally, she appeared in bright white-and-blue clothing and looking young. (COMIC: The Professor, the Queen and the Bookshop)