I was once in the marvelous Field Museum in Chicago, chatting to one of the curators, when he said brightly, "Maybe you can help with a question a visitor left in the box this week." He produced the inquiry, which ran as follows: "I was given an antique dream catcher. Ever since it's been in the house, I've had the feeling that something's just not right and I can't get any good sleep. Maybe I should cleanse the dream catcher or something like that?"
I smiled at the idea of an "antique" dream catcher. The original purpose of a dream catcher is to catch bad stuff you don't want in your psychic space. It looks like a spider web because that's exactly what the first dream catchers were. An Onondaga Indian friend of mine hung a literal spider web from a hoop, in the old way, over his son's face when he was a little baby. You do not want a hand-me-down dream catcher. More than likely, its web will contain traces of other people's "bugs" and psychic pests. "There's no way to cleanse something like that," I told the curator. "If it were mine, I would burn it."
In the understanding that dreaming is social as well as individual, most human cultures have come up with methods to deter unwanted intrusions or visitations during the night. There's a dream guardian in Japan who is rather livelier than a spider web. Here's how it is described in the opening of a folk tale about a girl named Little Silver who feared she would meet ghosts and demons in her dreams:
The old nurse told her to draw pictures of a tapir on the sheet of white paper which was wrapped around her tiny pillow... The nurse told her what many old folks believe,—that if you have a picture of a tapir under the bed, or on the paper pillow-case, you will not have unpleasant dreams, as the tapir is said to eat them. So strongly do some people believe this that they sleep under quilts figured with the device of this long-snouted beast. If in spite of this precaution one should have a bad dream, he must cry out on awaking, "Tapir, come eat, tapir, come eat!" Then the tapir will swallow the dream, and no evil results will happen to the dreamer.
In the story, this has mixed results. Little Silver's dreams take her on a fantastic voyage among ghosts and drunks whose excesses feed demons. At the end, she is terrified by the impending wreck of the ship in which she is sailing. As she wakes, she remembers to cry out "Tapir, come eat, tapir come eat!" This lifts the bad feelings around the dream, but she retains the memory of her adventures and can draw important lessons, including the consequences of to much saki. The narrator observes that it was a good thing she did not actually see the tapir, since it would have scared her more than the ghosts.
The tapir in this story is not the long-snouted pig-like mammal of the natural world. It is a baku a composite beast originally borrowed from Chinese folklore. In early Japanese depictions, this eater of bad dreams is portrayed with an elephant’s trunk and tusks, plus horns and tiger’s claws. Today the baku is also known as yumekui ("dream catcher") - perhaps a borrowing from North America - and in manga and anime it takes many forms. In Satoshi Kon’s animated film Paprika, a young woman is a baku who devours a dream villain in the climactic scene.
The idea of the baku, in a sense, puts the spider into the web of the dream catcher. I rather like the idea of a dream guardian who will eat bad energy from a dream without depriving us of the memory of the dream experience.
 "Little Silver" in William E. Griffis, Fairy Tales of Old Japan (London: Harrap, 1911).
Graphic: Baku byKatsushika Hokusai.