The Devs. Or the Game. Or the Master Copy of the Elder Scrolls timeline, if such a thing exists. The Imperial Library itself. The UESP Wiki. The Fans of the Series. Every Modder out there.
One explanation I've heard of CHIM (in fact, the first,) basically boils down to the idea that everyone who has acheived some manner of CHIM realizes that they're a fictional character in a fictional world, and decided to roll with it.
So, in answer to your question, the current CHIM creature would be...
Todd Howard.