2e. I was the DM and running a Dungeon adventure. The party is underground, finding a lost city. There's a black dragon extorting treasure from travelers in the caves, particularly silver coins as the dragon is an OCD coin collector with his hoard sorted, stacked, and alphabetized. There is a massive mushroom in the passageway and the dragon uses Ventriloquism to make it appear the mushroom is sentient.
The party (12 players) gets in a snit and decides to take the fungus down. An indiscriminate volley of fireballs & pyrokinetics later and the entire passage is in flames. The dragon is miffed at the loss of his prize mushroom and begins mauling the party. They had assumed a perfect battle line and he blasted virtually all of them with his breath weapon when he burst from his hiding place on their flank.
The dragon has a height advantage as well as seriously rough terrain between himself and the party. The two PCs with items of flight (a cleric with a ring of djinni flight and a psionicist with winged boots) charged in. The psionicist become a chew toy as the cleric's attacks did little good.
The wizard starts firing off flight spells and the rest of the party wades in. They make a critical error and once again line up, allowing yet another scarring line of acid catch them all. The cleric, having failed both saves, is horribly injured and flies down the hallway behind the dragon, entering it's lair. The dragon is enraged, but encircled by combatants. It takes it a round to maul enough PCs to break free.
In the lair, the cleric healed up some and snooped about. His ring of djinni flight creates a whirlwind, which had left a trail of disarray. When the dragon arrives, the cleric is hovering over the coin collection. The dragon becomes incensed as the carefully sorted coins are strewn about, in some cases flung halfway across the cavern.
The dragon is in a blind fury now, and unleashes a stream of curses as well as his last breath weapon, knocking the cleric out but not (quite) killing him.
With the exception of the kender, the rest of the party is regrouping (aka healing) before launching their counter offensive. The kender has stealthily followed the dragon, out of curiosity, of course. When she arrives the dragon is drowning the cleric in a pool of stagnant water as if the cleric was an unwanted kitten.
The kender looks around at the cavern and realizes something I (the DM) had not. "Oh my, dragon," she exclaims, completely in character, "you melted all your pretty coins! How sad!"
The dragon turns, ever so slowly, to look at the kender. Then, hesitatingly, as if against its own volition, it brings its eyes to bear on the ever so carefully sorted, stacked, and alphabetized coin collection.
Or what's left of a collection of silver coins when incredibly destructive acid is blasted right across the very heart of the collection. I (DM & dragon) am totally flabbergasted, nay, pole-axed. My brain has just thrown a gear and come to a grinding halt. I snap out of it enough to realize that if I'm this stunned, the dragon is orders of magnitude worse off.
The dragon sinks to the ground and curls into fetal position, moaning.
The rest of the party arrives to find the kender patting the dragon on the head and making soothing "poor, poor dragon" noises.
They very quietly retrieve the cleric before he drowns, grab the items that detect as magic and retreat before the dragon comes out of his psychotic breakdown.
