South Park: The Stick of Truth - Make This for You Achievement

Achievement - Make This for You
Fling a turd that you created at an enemy in combat.

First you must create a turd (looting one in the sewers doesn't count). This can be done in any bathroom. Go to a toilet and make a turd then loot your turd. Now that you have a turd, in battle, go to your Items, and pick the turd, then pick an enemy to throw it at. This will gross out the enemy and will unlock the achievement immediately.