Spoiler Warning!!!: Plot and/or ending details of a Fighting Fantasy publication follow. Please DO NOT read this article if you do not want foreknowledge of this publication. Although the article below is based on canon, some of its content is considered extrapolation because it assumes a certain course of events through an adventure that has many possible routes.
A ring fashioned in the shape of a serpent, it had been in the possession of beggar who was once the Seventh Noble of Kharé. He was under the impression that it protected the user against serpents and it had been his prized possession. However, he was willing to give it up to an adventurer who gave him alms.
The Serpent Ring forced the Serpents to reveal information, which was a duty set down by their gods. It is not known why this is the case. Otherwise, it offers no protection, other than perhaps delaying the attack long enough for the wearer to think of a plan.