Someone there at Blizzard has a thing for poo.
I should probably go off on one here about how immature the poo-related quests are and how they are really unnecessary etc, but be honest here, they make you giggle don't they :)
I just discovered another one today, in Hellfire Peninsula, called Shizz Work. Basically, a fel hound has swallowed Razelcraz's keys and you need to take it for a walk and sift through the felhound's 'leavings'.
After you've picked through the goods, you are left with the delightful debuff [Stanky].
I can take or leave the poo quest in Nagrand which I believe is called A Rare Bean, but doing the chain around Doing Your Duty in the Grizzly Hills always makes me giggle like a 12-year-old.
I'm sure there are more... have I missed one?