Monster Under the Bed: Fantasy - Children's?

The grimble snuffled softly to itself beneath the bed. There were no longer the tempting little feet dangling over the side. The dust bunnies grew unhindered under the bed. The grimble missed the squeaks and shrieks of the little boy who had lived above him. He had been most fun to terrorize, and when his feet had strayed too close, close enough for the grimble to nip, they had tasted excellent. Now the grimble's dinners were made of dust and old sheets, and the grimble was turning into a shadow of himself. It was intolerable. He demanded his boy back. He knew the child still lived--

Inspiration: None.
Story Potential: High. Oh-my-God-high.
Notes: A little boy is kidnapped, and the monster under the bed goes in search of him. This story could even be written for kids. Could be written as a picture book (what's under the beds that grimble looks under?).