With Moriarty, Doyle does such a brilliant job of writing a mafia don before they were invented. Every other supervillain ever since sounds like Moriarty. Goldfinger sounds exactly like Moriarty. He invented the supervillain. If you do him like that now, he sounds like the biggest cliche on earth. So we did a quite different kind of Moriarty, one that would be more alarming, I suppose, to Sherlock.

Steven Moffat talking about Moriarty’s character – (x)