From publisher blurb:
For whatever reason, magic rings have become even more popular with players as of late (hmm). Don't let them down. Give them a new ring every game.
Magic Rings I features 50 new magic rings for use with D20 fantasy settings.
This cursed ring is carved to resemble a demonic vestige. Those brave enough to wearer it, by sticking their finger within its fanged and gaping maw, will find it impossible to remove without the assistance of a remove curse spell. The wearer will suffer no ill effects until an hour has passed. At this point the ring will animate and the fangs will plunge into the wearer's finger dealing a painful point of damage to them and permanently drain 1 point of constitution. For each night the ring is worn it will drain another point of constitution. Once the ring begins 'feeding' its wearer gains two abilities. The wearer can perform a Draining Touch once per day. By succeeding at a melee touch attack the wearer can drain 1d4 hit points from a target as well as 1 point of constitution. The wearer is then healed for as many hit points as drained and a point of ring drained constitution is restored to them. The wearer of the ring may also cast a ray of enfeeblement once per day (as described in the Dungeons & Dragons Player's Handbook, Third Edition). The ray functions at the wearer's level and its point of origin is the eyes of the demon on the ring.