This is going to sound stupid, but what is the spirit turtle? (You listed it with the ghost grass in signs of the coming apocalypse).

Sorry, remembered it wrong, it’s the phantom tortoises:

“Xaro looked troubled. “And so it was, then. But now? I am less certain. It is said that the glass candles are burning in the house of Urrathon Night-Walker, that have not burned in a hundred years. Ghost grass grows in the Garden of Gehane, phantom tortoises have been seen carrying messages between the windowless houses on Warlock’s Way, and all the rats in the city are chewing off their tails. The wife of Mathos Mallarawan, who once mocked a warlock’s drab moth-eaten robe, has gone mad and will wear no clothes at all. Even fresh-washed silks make her feel as though a thousand insects were crawling on her skin. And Blind Sybassion the Eater of Eyes can see again, or so his slaves do swear. A man must wonder.”