Travel to Blackrock Spire and destroy the source of the worg menace. As you left Helendis, he shouted a name: Halycon. It is what the orcs refer to in regards to the worg.
You have no doubt seen the worgs which the Blackrock orcs command.
It is curious - no matter how many we destroy, their numbers never dwindle. My scouts have reported that the worgs are bred, trained, and ultimately exported from Blackrock Spire: capital city of the Blackrock orcs. You must travel to Blackrock Spire and discover the source of this menace. Discover... and destroy.
Good luck, [player]. May Cenarius protect you...