Stephen Hawking (pronounced 'Steven Talking' by his computer) is mastermind gifted whom is secretly trying to take over the world one field of science at a time, beginning with astrophysics and moving on to Molecular biology. The 5 1/2th incarnation of The Doctor, he has also done it with Billie Piper but not Catherine Tate. Shudder.
“Am I "bothered". Am I "bothered"... though. Look at my face. Do I look "bothered" to you.”
Steven Hawking's arch nemesis is Gaz, who appears at inopportune moments such as when Hawking is taking a dump, checking the football pools or singing karaoke.
Oh yeah, he's also a robot.