In Bitterblue, Po is a walking CMOF. During the book he:
Experiments with paper planes in the rain, and manages to fall off a ledge while doing this
Wrestles with Katsa while Bitterblue is attempting to work
In Bitterblue, a woman Graced with singing is hired as a prison guard. This gives us a chapter ending with:
They sat together at the top of the prison steps, listening to Goldie sing a lullaby to her prisoners.
The Dramatis Personae at the end of Bitterblue, which is apparently written by Bitterblue's librarian, Death. It's full of little snarks at people, and you've got his recurring opinions on the kings of the other kingdoms: "Vile miscreant." "Insufferable blackguard." "Contemptible scoundrel." Of King Ror, he says "Presumably not the ass the other kings are."
He also feels the need to include his pet cat in the list of characters, even though he regularly comments on other people that they are "of questionable relevance" to the record.