There is one for each city I think. I specifically remember talking to the one in Cabilis after they showed up when I played on Live.
http://everquest.allakhazam.com/db/npc.html?id=6399
http://everquest.allakhazam.com/db/npc.html?id=6656
http://everquest.allakhazam.com/db/npc.html?id=6705
http://everquest.allakhazam.com/db/npc.html?id=6849
There's more, but I'm on my phone right now and copy/paste is quite a chore. I know it was eventually found out that it a was GM reward quest, but I had never heard of them being killed or dropping anything, but I had also never heard of killing Bro Z/Q before either until way after they were implemented too. The one you listed is the only one that has comments regarding them dropping items that I looked at.