Stephen King has a surefire cure for writer's block. He pulls a jar from his desk containing the pickled heart of a slave child from the early 1800s. After just one glimpse, says King, "I can get inspired to write truly terrifying prose no matter how blocked I was before." As effective as his muse is, King doesn't rely on it too heavily. "I only pull out the jar on rare occasions."
Originally, the joke was Bob Bloch's -- he said, more or less, "I may write disturbing stuff, but really I have the heart of a small boy... I keep it in a jar on my desk." Steve King would occasionally quote it, usually giving attribution, as in "As Robert Bloch said, I may seem scary, but I have the heart of a little child. I keep it in a jar on my desk."
I just wonder what kind of process happened here -- my guess is that a foreign newspaper found the "jar on the desk" quote, failed to understand it was a joke, and decided to expand upon it, and the story was picked up and repeated. (Although it's always possible that someone asked Steve what kind of heart it was, where he'd got it from and so on, and he decided to test their credulity, as Terry Pratchett and I once did when we realised we were being interviewed by a radio journalist who hadn't realised GOOD OMENS was a work of fiction, and wanted to know more about Agnes Nutter and her prophecies.) But somehow I don't think so...