You pass through a woodland with a floor that seems remarkably clean of debris. Suddenly your attention is drawn to a twisted bit of wood by the trail side, a short broken twig with several stubs of branches along its length and most of the bark missing. When you reach it, the twig blurs and turns into a small brown lizard, caught in the middle of its body-twisting run. The little reptile darts away down the trail with impossible speed, no doubt magically enhanced, and is lost to sight in a moment. Now someone knows you are coming...
An evil ruler got the idea of mixing a trampoline and a gallows together. As long as the one to be hanged bounces on the rubber trapdoor it won't open, but bouncing gets very tiring after a while.