Dribble
Children generally have things under their beds: monsters, bogeymen, snakes, all kinds. Samuel Vimes Jr. has a dragon. Really. An old, toothless, flameless Swamp dragon who sleeps a lot, under the Hon. Sam's cot, with a little whistling snore. The old dragon's name is Dribble, which is fairly descriptive of swamp dragons in general, and he's not much good for anything except that Young Sam knows exactly what's under his bed.