The hierarchy of Jiangshi
I was reading an article about the Jiangshi at Baidu. Both English and Chinese. Even the Chinese Wikipedia about the Jiangshi.
In later volumes of Yuan Mei's Zi Bu Yu (What the Master Would Not Discuss), somewhere in volume 9, mention the classification of Jiangshi.
Classification and Ranks
Basic Forms
Purple Jiangshi (紫僵)/White Jiangshi 白僵/Green Jiangshi 绿僵/Furry or Hairy Jiangshi 毛僵: The lowest tier. Afraid of sunlight.
Prostrate Corpse (伏尸): A newly transformed corpse with a withered, blackened body, slow movement, and an inability to move freely. It often hides in damp, dark environments and preys on living beings through ambush.
High-Level Variations
Wandering Corpse (游尸) / Hopping Corpse (跳尸)/ Bronze Armored Corpse (铜甲尸): It possesses skin like bronze and bones like iron, making it impervious to blades and spears. Although its body is stiff, it can move by hopping and is not afraid of brief exposure to sunlight.
Flying Jiangshi (飞僵): It can leap onto roofs and trees, bounding swiftly. It fears neither sunlight nor swords. It can only be subdued by Taoist ritual implements or a heavenly thunder tribulation.
Ultimate Forms
Unrotting Bone (Ba)/不化骨（旱魃: A form of corpse that remains incorruptible for a thousand years. Having absorbed the Yin energy of the earth's veins over a long period, it loses its ability to move. While not aggressive itself, its presence can trigger regional calamities.
The Unrotting Bone (不化骨) are the dangerous variants. Unlike the basic one, they absorbs the essence of sun and moon over a long period and bring calamity to the world.