Dragons of Jenoa

On Jenoa, there are only chromatic dragons left. All of the metallic dragons have been extinct for centuries, having died in the last Dark Times, according to the legends. There are at least 54 of them controlled by the Knights of the Silver Dragons using the Orbs of Dragonkind created by Melchor Rivengol.

In this campaign, all dragons have the alternate form ability that normally only bronze, gold, and silver dragons can do (by the strict D&D rules). They have this ability from birth, but can only assume the form about the age they themselves are. For example, a black dragon wyrmling (a tiny creature) could only appear as a humanoid toddler.

Dragons thus can shift between three forms, a humanoid form (usually the Knights make their dragons have hair color corresponding to their dragon type), a hybrid form (like lycanthropes from the 5th edition MM p. 208-211) which is basically a humanoid with a half-dragon template, or their natural full-dragon form.