You've sworn you would kill the dragon that's been terrorizing the three kingdoms sharing borders with his immense lair. You've outfitted yourself with the best steel in all known realms, and you've finally braved his sulfurous depths. Just as the air becomes warm, you turn a corner and emerge into an immense chamber packed with gold, hoarded art pieces, and piles upon piles of books. You just didn't expect the twenty-feet silhouette of Scramasax the Red to be found seated in a gigantic throne, wearing a black three-piece and a necktie that are completely anachronistic to your Medieval fiefdom - and holding a pen and a notepad as if he'd been expecting you...
"Welcome, hero. You'll find I proceed differently from my forbears and my brothers and sisters..."
He clicks his fountain pen ominously.
"Simply put, rampages only lead to deferred hunger, and gold loses its lustre if it isn't entrusted to the handful of smallfolk who have any sort of need for it. I'm a dragon; I have no need for gold, no means of making it appreciate - and yet I've inherited this hoard from my predecessor. Considering, I'll be rather blunt..."
He leans in, a Brimstone-scented rumble shaking the ground as he comes as close to meeting your gaze as he can.
"Pitch me. Sell me on the value of leaving the adjoining fiefdoms be, when I could think of five or six vectors that would justify my... slaughtering a cow or two. Or three hundred. As payment, of course. Sell me on the idea that causing little humans an acute dose of concentrated grief isn't likely to have dividends in the coming generations.
Every pass of my flames renews the topsoil and culls old growth to make room for the new. Every life I take is a life that would not have endured the hardships of feeding two baronies per farmstead. Every death is one less mouth to feed. The local paladins see it as murder; I prefer to think of it as optimization. And I don't merely sit idly by surrounded by gaudy and vulgar displays: the same kingdoms you claim to be fighting for all receive the visit of a peculiar nobleman from parts unknown, every few years. Myself, under a veil of commonality and pedestrian size and proportion..."
He pauses to gesture. "Why, you could say I feed my own larder... Then, I come back wearing a different face, and claim a five percent surcharge as taxes on 'foreign business'. I keep them fed, they keep me wealthy, I invest in their economy and keep them fed. Round and round it goes."
He stops to steeple his fingers together, notebook in his lap and pen threaded between his fingers.
"So. Under this light, little human; pray tell why I should conceivably cease what strikes me as being the development efforts of a well-intentioned financier. Pitch me an alternative. You have five hours to prepare. I'll expect a full deck at dusk."
He straightens and fixes his necktie, giving your sword a look of vague disgust and pity.
"Do put that away; I might as well use it as a toothpick."