Four items from Oracle of Seasons that are both keys and weapons.
Gnarled Key: The first key Link obtains in his travels through Holodrum is given to him by the Great Maku Tree after Link rudely wakes him up after winning the sword from the Hero’s Cave. The key opens the first dungeon, the Gnarled Root Dungeon, just north of Horon Village and Impa’s hut.
This weapon is a root of the world tree that grew around a rare piece of the world that was before. With the primal energies stored in the wood and stone, this weapon can bend and warp itself to match the users any whim, and it is the only offering the great bramble witch will accept to visit her well of knowledge. It is either part with the root, or raise it in violence.