Tulpa

Asunder was the first to see her. The clan leader thought it was just a figment of her imagination when she saw the regal head of a vast dragon rising over the Wyrmwound. But then the reports started rolling in: Azazel and Kasala saw her on the battlefield, a brief glimpse of tattered, mottled wings in the distance; Astera told tales of a winged shadow crossing her eye as she stargazed one cold night; Stargardt shook her mate Cotard awake one night, frantic, pleading that he guard the hatchlings from some apparition her poor eyesight could barely make out. The clan was troubled. Asunder and her mate tried to quell suspicion, but they were troubled too, and it showed.
Sightings of the mysterious wyrm continued, but tension in the clan began to dissipate after many days of the apparition proving harmless. It eventually became commonplace and even expected to see the shape of an elegant Imperial in the corner of one's eye.
No one took credit for the idea, but it became accepted to leave offerings for her: a pile of emeralds here, a pile of daisy petals there. She began to show her face around the clan, still silent, but impassive and watchful. They called her Tulpa.
Through all this time, they never figured out what she was. A normal dragon who just happened to be very shy? A ghost? A complete work of fiction whose only sentience was that granted her by the clan's imagination?

who knows but hey, she got a gijinka