A Facebook friend, Kyla Fournier, placed as her status the observation that "Even the monsters under the bed have nightmares." The comment lit a spark of imagination in my mind.
Another of Kyla's friends commented that the monsters have nightmares about the people on top of the bed, which would be ironic. Of course, when we imagine creatures actually dwelling below the bed frame, we enter the world of the surreal. But even a surreal story should have a certain internal consistency, IMHO.
A monster afraid of the person on top of the bed is consistent in a way. After all, if it's a monster, a powerful brute of some kind, in theory it should be able to come out any time it likes. But no, it goes under the bed and stays there--perhaps because of a terror of those who dwell on the mattress up above...
But a creature dwelling under the bed terrified of us rather ceases to be a monster, doesn't it? After all, the creatures of Monsters Inc feared contamination by children and that fear made them mostly cute and lovable. And the childhood fear of the unknown darkness dwelling right underneath where I'm sleeping certainly is downplayed by thinking the monsters are not actually, well, er, monstrous. So let's move past "the monsters fear us" theory.
Another kind of irony would be to think that just as much as we instinctively fear what we imagine dwells in the narrow dark space below us, the monsters fear the light of the open world above. Which is why it's absolutely essential that a child have a nightlight...because without it, the creatures really will come out from underneath the bed...
So maybe these creatures have nightmares about light. Or being in the open, away from the bed, a kind of monster agoraphobia.
But if we're to play on the irony of the monster being like us, only different, then it's significant to note that while I was terrified of darkness as a child, I never had nightmares about darkness itself. Instead, my bad dreams were about creatures dwelling in the darkness, creatures that do not just passively inhabit the realm of the things I cannot see, but which will actively come after ME, given half the chance.
So doesn't it make sense to think the Beasties Below Bed (if this were a military operation, this would probably become an official designation "BBB," as in "actions to deal with the BBB threat") also fear some terrifying creature of the light that invades their world, something that comes after them where they dwell?
I have something specific in mind. And it even makes a horrific sound, not unlike a scream.
I think the monsters under the bed have nightmares about vacuum cleaners.
Think about it.