Skull Hammer

The Skull Hammer is found upon returning to the Forsaken Fortress and defeating Phantom Ganon. It is used for hitting switches and enemies. When used it causes shockwaves which can stun nearby enemies. It can also be swung sideways to knock enemies for six.

This is the key to defeat Helmaroc King.

Other hammers

 * Hammer from The Adventure of Link
 * Magic Hammer from A Link to the Past and Four Swords Adventures
 * Megaton Hammer from Ocarina of Time