I was sitting for initial aggro (and 1 round) and max hit was 2214. I believe my shielding is around 21. That would put his max hit much more in line with prackers's figure than the 10,000 quoted above.
finally~! i found it~!LOC is P99,P44 ~~!! it's at 2nd floor.SouthEast bubble. the 2 mob in front of the lift are both PH. left side 4 mob and right side 4 mob are not PH. never pop when i exp there after 10 hrs.
Actually, all gnome models are PH's. This means that every gnome standing around the central "cage" can spawn Wripple, so the more you can kill the more chances you have at spawning him. I can verify this, as I've seen him spawn in just about every spot around the cage in the room. Most named in the expansion are this way; they spawn in a particular area, with a certain model being a PH.