zhū chēng yè guāng
"A pearl called Ye Guang."
Unlike the name of the sword in the last entry, 夜光 makes sense on its own: it means something that shines at night.
Paar says that the story of this pearl comes from a book called 搜神記, or the Record of Searching for Spirits (my translation; my phone's dictionary calls it, in a much more modern fashion, In Search of the Supernatural), published during the 兩晋 Jin dynasty (the first one(s), from the third to fifth centuries CE): "[t]he Marquis of Sui rescued a wounded snake, who in gratitude brought him a pearl that shone brightly at night."
I don't have a problem with snakes. Like a lot of things in life, as long as they're left alone and not hassled, they're usually content to reciprocate. I especially like this snippet of a tale for demonstrating that not all snakes of yore get a bum rap, like the one in the Bible, and that everyone, even presumably busy Chinese noblemen, can do right by their fellow sentient beings. Of course, the full story may end badly, but I'm gonna leave it as it is for the time being.
Until next time, folks!