You'll know this guy is up because plenty of spam about terrible terrifying creatures clawing their way to the surface will spam the entire area, easily heard from Clifton.
This little rock formation is straight across the river from clifton, follow the wall straight up, and follow the rock wall. Make sure you have good Clifton faction, else Lamias, cliff yaels, and grifons will make your life miserable. (Easy, kill undead locally.)
At all costs, get out of the area if you're exping, when you see the first emote. The entire area clear to the river floods with Dark Splinters, and worse monsters. =) It'd seem like good exp, but they're thick as flies. You've been warned.