This is a concept I drew yesterday for Hexartus, the most familiar genus of dragon found in the Stablehand universe—more commonly known simply as the hexart. Hexarts are very unusual among animals not only for their crazy number of limbs (hexa- six + artus limb), but also for their incredible power of metamorphosis. Although all of them begin life looking somewhat like the juvenile above, at a certain point many individuals undergo a drastic transformation that leaves them looking wildly different as adults. The process is not well understood, but in many cases, an individual's adult form tends to relate in some way to its specific experiences and other organisms it encounters. An adult hexart may end up looking like a blue jay, a lion, or theoretically even an oak tree in bizarre enough circumstances. Some have even taken on adult forms that resemble humans, although for some reason none have been found that have a perfect resemblance, and most of that sort have retained some obvious indicator of hexart-ness such as scales or a tail. It also remains to be seen whether any of them can actually learn to speak human language.
Hexarts are not shape-shifters. They can only transform once, and once they do so, there is more or less no going back. To a culture that grew up with their existence, they would probably be a symbol of greatest commitment and selflessness, as well as a convenient subject for a cautionary tale when needed. They would also likely be a good metaphor for a criminal that dives into the shadows and tries to hide behind limitation statutes and other protections to escape punishment.
Red, the dragon I posted a picture of earlier, is a hexart. That should give you a small taste of what the species is capable of.
Also, have a fantasy cladogram for the sake of silliness.