The Daily Spy Hunter, in Storm Peaks, requires you to blow a horn on a wolf which then summons a ghost wolf, who runs around looking for a dwarf you need to kill. You must do this x3 to turn in the quest.
The quest takes about 5 minutes because the wolf is slow, however.
If you mount up, the dog runs faster, and may find the dwarf under 30 seconds.
This is a Daily Quest, which you get with honored rep with the Sons of Hodir Faction.