John Simian played the severely deranged Mattress during the Tenth and Twelfth Doctor's era.
Simm /who/ Edit
Simm has a loyal following on /who/ known as Simmchads.
Simm appears in Utopia, The Sound of Drums, Last of the Time Lords and the two-part Christmas special The End of Time.
And now Series 10. Officially confirmed now, apologize to the Moff.
And now tired old memes
that only the oldest, saddest virgins on /who/ would have any recollection of.
If I see that fucking Master one more time...