[Slenderman - Doctor]

Originally Posted by Captain Harkness

Tegan knows the brigadier and SJ says that she knows a woman in Australia called teegan but she knows it's teegan cause they meet. A random dalek came from where?

Tegan knows the Brigadier as they met in "Mawdryn Undead".

The Dalek was a left-over from the Game of Rassilon, as were the Cybermen and the Raston Warrior Robot. And the Yeti.