Duc
A frog who struck it lucky, or so he thought. Against the usual run of these things, a witch turned this frog into a human and offered him a Dukedom. Nominally the Duc of Genua (could there be a Quirmian connection with this title?), he wore thick sunglasses to conceal his giveaway eyes, as eyes can never be changed in any magical transformation.
This slightly existentially confused frog, who became human, who became a Duc, is just a prawn (er, pawn) in Lilith de Tempscire's foul scheme to supplant Baron Saturday as ruler of Genua. Unfortunately mere death has not stopped the Baron being a focal point for opposition: he has returned, fittingly for the home of voodoo magic, as a zombie.
Lilith, who knows stories, knows it only needs the right kiss at the right time to make the Duc human forever and to seal his right (within the power of narrative causality) to rule Genua.
Enter Granny Weatherwax to thwart her sister's scheming, supported by Nanny Ogg and Magrat Garlick.
The Duc, whose bedroom is unique in that it contains no actual bed, but a covered pond (Duc-pond?) and plenty of flies to snack on, is returned to froghood and a brief despairing crunchy Ribbit under the boot of Baron Saturday.