This is the dragon ring Quintus wears along with a second ring, first on his left ring finger in the episode "Revelations" and then on his right ring finger in "Kill Them All." There is only one really good closeup that I can find that shows the curl of its tail in the last episode of the season, when he is peeling an apple, and the screenshot is much darker than the live shot of it. However, he is wearing the same set of rings almost throughout 1x12-13 and "ends" with it on, IYKWIM. The ring is silver with an aged bronze patina on it.
