Crabbadon

I've rubbed myself up against the *entire* perimeter of that area and no dice, including the only bit of wall in the area (I've already been through one wall and a tree)

I'm on the quest where you hunt down Theresia; I've just come across the water and wandered all around the perimeter of that area, but even though I can see a big obviously mismatched tree, my shaman won't notice it.