In-Game Description
A strange key shaped like a wild beast's fang.
What manner of dilettante would create such a
key, and what might it unlock?
Use
Opens a door in a cave in the cliff near the Shaded Woods Shaded Ruins bonfire. This frees Weaponsmith Ornifex.
Go to the open area past the bonfire with Lion Clan Warriors and drop down the boarded-up hole in the ground. In Dark Souls II the Giant Basilisk is in this area, in Scholar of the First Sin it's empty. When you drop into the hole, beware of Basilisks.
Availability
Use a Fragrant Branch of Yore on the Lion Clan Warrior visible to the right of the Shaded Ruins bonfire, across the gap.