While having no magical powers imbued within them, glow-in-the-dark Wishbringer replicas are highly sought after, even to the point that dragons have been known to horde them.

Two people are definitely confirmed to have been in possession of these replicas at one time. Zot Brastar, after stealing one from a dragon, had one that he claims he was possibly willing to exchange his to an unknown adventurer for the egg of a Queen Corbie. The other was the famous unknown Festeron Postal Worker.

SOURCE(S): Beyond Zork (sample transcript)