This site lists any interactive entity that isn't another player character in the game as a 'mob.' That's the generic term. He's not a monster and thus you can't kill him for experience, treasure or to fullfil a quest, but to call him a 'mob' is not a mistake. Did you notice the 'NPC' tag in the description?
This is the guy who gives you "Mentor" status which I highly recommend doing. Enhancing the experiance for n00bs is actually kind of fun. You can turn it off also by doing /mentor off