Auto-rotator
Move the sliders to design your auto-rotator.
With scissors, cut all of the solid lines.
Fold all of the dotted lines (the two body lines first, the hook line second, and then the two propeller lines).
After folding the propellers in opposite directions, fluff them up so the auto-rotator looks like a capital Y.
Safely drop from a given height, and watch it automatically rotate gracefully to the ground.