The fishing daily Armored Carp from the Anglers in MoP, asks you to kill 5 Armored Carps using a spear. If you have done this quest before you know it sucks because the spear is horribly designed to blow at aiming but I found out that you can simply auto-attack them which brings about an instant kill and they still drop the quest item you need.
This may be considered a (mini) guide but I believe it's an exploit since obviously it is not working as intended since blizzard wants you to use their spear to complete the quest.