血滴滴的 Dripping Blood Rolls Out
這個真正是唐老爺的頭，我大王留了鎮宅子的，今特獻出來也。」撲通的把個人頭又從門窟裡拋出，血滴滴的亂滾。这个真正是唐老爷的头，我大王留了镇宅子的，今特献出来也。」扑通的把个人头又从门窟里抛出，血滴滴的乱滚。
逐句解 Line by line
This one is truly the head of the venerable Tang. Our Great King was keeping it to ward the house, and today he presents it to you specially."
鎮宅 is to steady or guard a dwelling, the language of a protective charm hung over a door — the fiends are claiming they had installed a holy man's skull as a household talisman. It is a grotesque compliment, and it is calculated: they are telling Wukong his master was too valuable to waste.
With a thud they pitched the human head out through the hole in the gate again, and it went rolling about, dripping with blood.
撲通 is the sound of something heavy landing, and it is the exact noise Wukong told Bajie a real head would make — the demonstration he gave two passages ago is now being played back at him as proof. 血滴滴 doubles the dripping, and the 血 takes its colloquial reading here rather than the formal one it carries in verse. The passage ends on movement: the thing will not even lie still.
The trick works because it uses Wukong's own test against him. He established the rule that a real head lands with a dull thud and no ring, and the fiends have supplied an object that satisfies it. His reasoning was sound and his conclusion will be wrong, because the premise he could not check was whose head it is.
That is the sharp edge of this whole sequence. The first forgery failed because it was a bad forgery. The second one succeeds because it is not a forgery at all — it is a genuine human head, belonging to a person nobody in the story ever names. The fiends beat the test by telling the truth about the object and lying about the man.