Dragon horn

From Harry Potter Wiki

Dragon Horn
Object information
Manufacturer	Dragon
Usage	When powdered down, can be used in various potions
Owners	Dragons
First appearance	Fantastic Beasts and Where to Find Them

Dragon horn is a common potion ingredient.

The powdered horn of a Romanian Longhorn is highly valuable and used in many potions. However, the excess trading of it caused the numbers of Longhorn to fall considerably, and so the horn was rated a Class B Tradeable Material.

The role of a dragon horn in potions remains unknown, however, like most dragon parts, it is extremely magical.