Grond (called the Hammer of the Underworld) is a fictional object from the works of J. R. R. Tolkien.
In the First Age, Grond was the great hammer of Morgoth, who wielded it as a mace when he fought with Fingolfin. During the War of the Ring, in the Battle of the Pelennor Fields, a great battering ram one hundred feet long and shaped like a snarling wolf named after the first Grond was used to break the gate of Minas Tirith. Aided by a spell of the Witch-king of Angmar, and the spells cast upon it during its forging in Mordor, Grond destroyed the gate in four blows.
