Ruth is the sole white dragon of Pern. He is ridden by Jaxom. In proportions, he is a throwback to the first Dragons. However, he also appears to be the most intelligent Dragon, though also filled with a childlike enthusiasm. Considered a "sport" dragon, it is not anticipated that Ruth would ever fly/mate any of the green female dragons.
Ruth and Jaxom played a crucial role in retrieving the Queen Egg that the Oldtimers of Southern Weyr had stolen, and thus, preventing war from breaking out between the Northern and Southern Dragonriders.