Diamond Crab

It grazes the cloud tops of Uranus where the diamond rain falls, and the rain takes root on its back: every hailstone that lands grows into a spire, until the carapace is a geode bristling with crystals, no two of them pointing the same way. It is slow and does not start fights, but strike it and it pulls in under the stone and waits; the great left claw has snapped harder things than a suit.