Spaltzahn

Rendfang can actually move in a very wide area; I found him running just next to Quarrystone Base Camp, and an addon I have defaults the spawn location as /setwaypoint 5770 4500 in the north. You'll probably have to set up a /targetexact Rendfang macro and run along the path on the map between that area and the lake below Quarrystone to cover the movement range.