Costume designer Howard Burden had this to say about 12's costume:
"Simple, stark, and back to basics. No frills, no scarf, no messing, just 100% rebel Time Lord."
In other words, a perfect canvas for the internet to paint on.
British actor Peter Capaldi will play the 12th incarnation of the Doctor.
You might recognize him from Torchwood or from the Fires of Pompeii episode of Doctor Who, in which he played Caecilius.