To earn the title The Crusher, do one of the following:
Talk to Lead Belcher, an Ogre in Barak Varr at 49.2k,57.9k. Follow the road southeast of Thane's Defense, and head towards the eastern exit from Barak Varr to the Marshes of Madness. He is standing next to a Cannon, holding a BFG, in the Dwarf Camp just west of the path, as you near the southern mountain range. The camp is on the hill just past the last Signpost along the road.