This is a concept for Dragon Cave, suggested by Hawktalon. It is not to be used elsewhere.
The Harptail is born with a few long thick hairs on its tail. As the dragon grows, these hairs eventually fuse to form the strings of a "harp". A dragon plucks the strings to find a mate that complements his/her unique melody. While the female has a lyre-like tail, the male's tail is more reminiscent of a concert harp.
I love your work, as always. <3 As Hylanvahr said, I also adore the glowing swirl patterns. Lady, you're so talented with pixel art. The swirls are pretty and bright, but then again then don't stick out.
Man, love those glowing swirl patterns on the wings! At this resolution, they blend so well (the anti-aliasing is incredible), and you really see the depth with the harp(?)tail and arms playing over the other wing. I think no one does dragons in pixels so creatively like you.