Been killing Harpies on-and-off all day. This spawned and hit for up to 690, but rarely (1855 AC). Had about 1/3 more HPs than the other harpies. Can be slown. Spawned or wandered on/onto ledge leading down from Mestle, p3900, -465, n97. Dropped the tool kit and some Fine Silk.
Spawned on the fourth isle loc 4271, -2150 -252, im pretty sure it just popped as i was killing a griffon, i dont think it walked up. I also killed a harpy explorer at the exact same spot.
Spawned for me on the fourth Island (island before the Island with the Captain on it) was on a small island at Loc P 4417 N 825 elevation N 9.43
Ive said on another post or two Im skeptical there are spcific PH ers because I have seen minis spawn in different spots and on different islands. Its seems more of a radom thing to me like any harpy can be a PH for the any mini named harpy its just random if a mini will spawn or a trash mob. thats IMO