Do not be alarmed. I am Theocritus, High Mage of Tower Azora in Elwynn Forest. The pendant you are holding is a method of communication between the Shadowhide Gnolls and their master, Morganth.
Through months of research, I believe I too can communicate through these pendants. If you can hear this message, then my spell was a success.
Bring me this pendant and I will reward you for the service.
You have my gratitude, <name>. I sent that message to the Shadowhide Pendants weeks ago and had believed it a failure. But it seems the spell did reach at least some pendants, after a significant delay.
In time I hope to learn how to send an attack through the pendants, to immobilize any Shadowhide Gnolls who wear them.
But before that is possible, I'm afraid that much more research is required.