I camped some Hollowshade rares last night, with this item as my main target. I culled the wolves on the hill for about an hour, then Curfang popped. He dropped this the first time, and I moved on.
For the difficulty involved (just patience) this is a great item. I'm glad I didn't shell out for an Idol of Thorned or Goranga Idol. Both of these are better, but this has resists, and was free.