Horsetail is an item in Paper Mario: The Thousand Year Door that heals 3 HP. It can be found in Petal Meadows in one of the candy cane-like objects strewn around, the one that gives you the item is found to the rightmost of the area just before you reach the bridge. You will know it is the item-giving one if it shoots down when you hammer it, and doing so ten times gives you the Horsetail. Leaving the area and coming back will let you obtain more, and after spewing out of the object that contains it, it won't last long, so grab it quickly. Its main use seems to be combining it with a Turtley Leaf to make a Fresh Salad as an alternative to a Golden Leaf, which is slightly harder to obtain. In Super paper Mario, Horsetails can be obtained from defeating poisonous enemies.