Bronze dragon
From Ardrana
Bronze dragons are inquisitive and fond of Humans and demi-Humans. They enjoy polymorphing into small, friendly animals so they can unobtrusively observe Humans and demi-Humans, especially adventurers. Bronze dragons thrive on simple challenges such as riddles and harmless contests. They are fascinated by warfare and will eagerly join an army if the cause is just and the pay is good.
At birth, a bronze dragon's scales are yellow tinged with green, showing only a hint of bronze. As the dragon approached adulthood, its color deepens slowly changing to a rich bronze tone that gets darker as the dragon ages. Older bronze dragons develop a blue-black tint to the edges of their scales, similar to a patina on ancient bronze armor or statues.
Bronze dragons speak their own tongue, a tongue common to all good dragons, and some hatchling bronze dragons have an ability to communicate with any intelligent creature.
Note: Bronze dragons originally appeared in this form in the 2nd Edition Monstrous Manual for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.