Ossavitor

Ossavitor was a great wyrm dragon of unknown sex and breed who lived during the time of the First Flowering.

Reputedly, around, Ossavitor successfully developed a magical means by which a dragon could attain immortality, a goal vitally important to dragonkind. In effect, Ossavitor's Way, as it became known, would allow a dragon to live forever in three separate dragon bodies. By the 14 century DR, many dragons like Eldenser had pursued it, while other dragons and the Cult of the Dragon had tried to destroy all evidence of the Way.

As for its originator, Ossavitor was presumed to have long ago either moved to another plane or to have died,  which may cast some doubt on how effective the Way really was.