I was recently treated to a surprise party and the cake was D&D themed. The main cake was a DM's Guide book upon which sat a dragon's hoard and a black dragon with eggs sleeping atop it. The hoard was created from chocolate coins wrapped in gold foil. When removing the hoard of coins from beneath the dragon, some of them were coated with bits of the caramel icing from the book cake below, and this got me thinking.
In the real world (you know, the crutch for people that can't handle fantasy) hibernating creatures do indeed defecate and urinate during their long sleep. In fantasy, dragons are said to sleep sometimes for centuries between rampages. While it doesn't really matter for telling stories it might be fun for DM's that like to gross-out, inconvenience, or otherwise poke fun at the players and their characters, to add dragon feces to the list of things found in a hibernating dragon's hoard.
While nearly all fantasy stories completely ignore the unclean aspects of reality, unless we're talking about Game of Thrones, it might be fun to explore how much more difficult for our adventurers these things can make recovering treasure from lairs. Over the dragon's lifetime it has accumulated wealth during each rampage and then hibernated upon the pile creating strata of secreted waste that a geologist could use to determine the age of the beast and maybe when each rampage began and ended. The collection of filthy lucre would have things glued together, stuff that is a challenge to identify, and would add weight and bulk to what is collected.
"You're trying to pay for a room at my inn using shit caked money?! Bunch o' fuckin' murder hobos, get out of my tavern!"
Admittedly, walking around with packs full of loot reeking of dragon waste may keep some creatures away from the party, it is just as likely to draw others to camp. "Do you want assassin bugs? 'cause that's how you get assassin bugs." Imagine crossing through another dragon's territory leaving a trail of scent along the way. Will the offended dragon follow the scent trail to the party or back to the rest of the hoard? If to the hoard, will it be there should the party return for more treasure, or maybe to the town where they carried the loot? The odor of dragon waste might make for an interesting problem to overcome.
If any reader has done this or does do something like this please come and comment a brief bit about how the players reacted. Hopefully it's some funny shit.