A group of 20+? I ran Wailing Caverns a few times with five and we never failed to get all the Fanglords. Now, only one of those groups successfully brought down Verdan the Everliving and Mutanus the Devourer, but that's enough for me. Gosh, that Verdan does hit hard!
My favorite quest is the Leaders of the Fang quest. Why? Because you get an AWESOME staff as a reward! As a shaman I've always liked having a shield, but the damage on that staff is righteous.