Taste of Death
The Ghoul Dragon haunts civilization. It has never been seen, not physically, but shrines propitiating the dragon dot the countryside and it is rumored to speak through the dreams of a favored few. It is never a mystery when the Ghoul Dragon lurks under a city, though. First the graveyards collapse, consumed in a massive sinkhole. Society falls quickly thereafter, as the rich and poor alike eat and drink and squander everything in the city. What would be the use of doing anything else? The Ghoul Dragon will devour it all anyway, and no one ever escapes it.
Oddly, the Dragon of Gluttony favors authority. It seems to preferentially target hot beds of rebellion or conspiracy against royalty.