Quote Originally Posted by sktarq View Post
I assume you are talking about the mercury.
Mostly I came up with that for a few reasons...
One mercury was a display of wealth material like gold or ivory for a long time. Aztec, Egyptian, and Chinese tombs all have been found with the stuff as a status marker. It has even been used as "water" in large models of palaces etc (where I got the idea) and is thought to have been used as a bed in another case. And this is by humans, another apex predator.
The idea of it being a concentratable toxin is rather new view of mercury.
I do assume mercury gets labeled by Detect Poison, or whatever other equivalent you'd have available.

Second, humans are omnivorous and most of the meat we eat is from primary consumers. There's a reason mercury is considered a bigger problem in tuna than in venison. When you eat something containing mercury, it builds up in your system. Particularly if a creature is eating a lot of large fish, its mercury levels are going to build up a lot faster than they do in a typical human. And of course dragons also live a lot longer, so there's more time for it to build up.

Of course, all of this can be hand waved for a game setting. I just figure a lot of parties are going to start wondering about what a dragon (particularly a metallic) is doing with a bunch of mercury.