Before the First Curse
The Dragon had long ago a daughter and for unknown reason he lost her.
Sometime ago, he came to the Land Without Magic and started a healing clinic, healing uncured diseases using magic he brought from his land. While being a healer, the Dragon also took some interest in the Author, mainly researching about him.
During the First Curse
Later on, Tamara comes for his aid to help her cure her cancer. As payment, she gives a picture of herself with her grandmother. August Booth then sees him in hopes of the Dragon to prevent himself from turning into wood. The Dragon reveals that he knew who August was back in the Enchanted Forest. The Dragon asks August to give him his whale shaped ornament and later ten-thousand dollars for the cure. After stealing it from Tamara, August hands him the money and the Dragon gives him the cure. Tamara later returns to the Dragon's clinic, where she reveals herself as a person seeking to remove magic from the land. She then kills the Dragon using her taser and escapes. His course was discovered by August later. The Dragon's research on the Author is then taken by August.
After the Third Curse
The Dragon somehow survives, likely having faked his death, and is visited by Mr. Gold and Regina years later, seeking help to open a portal to another land to rescue David, Snow, Zelena, Hook and Belle. The Dragon however was not powerful enough to open the portal and merely got a glimpse of David, Snow, Zelena and Hook in the other land. The Dragon then states that all of them, including Emma, Henry and Violet that they did not try hard enough to believe in magic in the Land Without Magic. The group then leaves.
Sometime later, after Regina managed to separate herself from her Evil Queen persona, the Evil Queen appears at the Dragon's shop. Now as a whole, the Evil Queen rips out the Dragon's heart, and imprisons him in the world behind the mirror, where Sidney once lived. After Regina and Emma get trapped with him, he aids them in escaping, until the Evil Queen takes control of his heart and turns him into a dragon. The Queen tries to use him to kill Emma and Regina, but is unsuccessful.
The Dragon is later freed by Regina Mills who succesfully undones most of Evil Oueen ( Serum ) works.