Kilgharrah

Kilgharrah, also known as the Great Dragon, is a mighty and ancient dragon who was the mentor of Merlyn, a tweenage witch at the age of twelve.

Merlyn Pendragon
Merlyn first met the dragon on her third night at Camelot, where he was proud to finally meet her (but he does admit, most people thought she was going to be born a man, not a young woman. However, the dragon respected Merlyn and saw her as a sister after they became spiritual siblings through Merlyn inheriting her father's abilities.

Morgana Pendragon
At first, Kilgharrah thought she would bring about eternal darkness with Mordred. However, Morgana proved to be different and learned that she was "Faye" to the Druids, especially after hearing the druid boy call her so.