I finally found this guy! He's in the SE corner of the zone, somewhat north of the baking supplies merchant. Loc is neg 1137.7, neg 1727.29. When I saw him, he had his pet and six gnomes (at least one of which was a caster) with him. I didn't fight him yet...the surrounding gnomes all conned white/yellow, his pet conned yellow, and he conned red...all indifferent....to my level 8 'chanter.
First time I faced him with my lvl 12 chanter, took him down with no problem. The next two times, however, I tried duo'ing him with a magician partner and had some trouble. As a necro, he will cast fear. If your pet kills him while you're feared, he will poof and leave no corpse. So be sure to cast Lesser Shielding and do what you can to interrupt his casting.
Third time we duo'd him, we got him before he summoned his pet. I chain stunned him while the mage's air pet whacked him to death. Very easy kill using that strategy.
His spawn time is one hour exactly. He can't be single pulled at that level, so using Lull on the other surrounding mobs is vital. Without Lull'ing them, you'll end up pulling four mobs when you attack him.