The Dream Eater
The baku eats bad dreams. A picture of a baku under the pillow nearly guarantees a good night's sleep.
Some sources say it has the nose of an elephant, the eyes of a rhino, the tail of an ox, the feet of a tiger, and the body of a bear. That chimerical image is probably closer to the Chinese mythical creature it was before it traveled to Japan. Over the years, turned into something different. I grew up thinking it looked like an anteater. Exactly when or why the transformation happened I don't know.
Bad dreams are important for baku, but there is another element essential to the baku's diet: steel. Baku can't survive when the world is at war, because all the steel gets used as weapons and there is none left to eat.
So steel and nightmares must be made of similar substance. That's something to think about.