Monsters and aliens
"There are some corners of the universe which have bred the most terrible things. Things that act against everything we believe in. They must be fought."
While the Doctor's fellow Time Lords are content to observe the universe from their home on Gallifrey, the Doctor takes a stand against the things that he percieves as evil: things that threaten, enslave, terrify, invade, or merely pester. Here's a look at some of the menaces that the Doctor has fought against:
