From what I've read, with some kings, if they won't take a pink, may take a small lizard (anole). I've mainly heard this with the Greyband kings, though... At a foot and some, he's certainly large enough that he's eaten before.

How long have you had him? Who did you get him from? Was it a petstore or a breeder or a friend? Someone you can ask about his feeding habits/patterns? Sometimes they like you to dance the food around in front of them, if you're feeding just frozen, or you could try with a live pink as the other posters suggested.

He may require a vet visit if he's still not eating for too long to see if something else might be wrong.

Good luck with your li'l fellow! I hope he eats soon.