King Buttermilk is the evil king of frogs, who reigns from the Magic Happy Room in Japan. His reach is worldwide, and will follow those unfortunate enough to spend a night in his domain no matter where they may flee.
Pretending to be a friend to children, he gains their trust before his evil nature is revealed. He then devours their souls, using their bodies as firewood. There are endless stories about the terrors caused by King Buttermilk, each more horrible than the last, but alas too disturbing to be recorded in written form. The frog king's foul exploits do enjoy a thriving oral tradition, as his victims-to-be tell each other stories as they attempt to find a brief, fitful sleep.
There is evidence that the staff of the Japanese hotel which houses The Magic Happy Room are likely thralls of King Buttermilk and aware of his terrible deeds.