I had trouble finding this guy - and the Clickit one - (you have six 'an ancient trilobite's" in the room any of them can spawn the Clickit guy - mine was the front left position where others said back right) but I think ANY of the mobs of the same mob 'type" can be replaced with the named - I got my by killing every "a spawn of Vergalid" in the spiral down to the bottom. As a rogue solo I dont track so just kept at it found a cliff overhanging that I was able to climb and 2 of the "a spawn of Vergalid's" were on the ledge way up and after my "Har`Lak the Ancient" first clearing I spotted this guy just hanging out - not by any blue crystal and way up too far to throw or cast a "clicky" at but I climbed up and finished the hunter task.
Good luck! and remember to "Be well and Kill often!"