I found three by a campfire by Lady D, theres also one that spawns outside a building ac ross from the building that houses the shark pool. The ones by the campfire can be single pulled, as to the roamers just have to time your pull right.
I ended up getting lucky, pulling them at the right time and having no wanderers add..infact when I killed the last one of the three is when the wanderers started coming around.
They are lightblue to a 52.
I fought them on my 52 zerker, I was able to take all three of them on at one time, being buffed with virt and shammy buffs, only 22% haste, had about 4.6khp, when the third died I was at 20% left, did use one HoT potion but didn't seem to help much.