地龙 ('ground dragon') is the Traditional Chinese Medicine name for the earthworm — a flatteringly mythical name for a humble creature. Dried and processed, it's used in formulations for fever, asthma, and stroke recovery. The species most commonly used is
广地龙 (Pheretima aspergillum). The everyday non-medicinal word for earthworm is
蚯蚓 (qiūyǐn).