Grond

The vast battering-ram brought up by the forces of Mordor to break the Great Gate of Minas Tirith during the Battle of the Pelennor. Grond was of monstrous dimensions: a hundred feet in length, capped with black steel forged into the shape of a wolf's head. It was covered against assault from above, and mounted on great chains. The whole ram was drawn across the field by great beasts (of what kind we are not told).

When it reached its target, its crew of Mountain-trolls drew back the ram, and pounded it against the Great Gate. Under the command of the Lord of the Nazgûl, they swung the ram three more times, and on the fourth impact the Gate broke apart in a flash of lightning (the result, it seems, of spells of destruction laid on Grond by its makers). With the Great Gate destroyed, Minas Tirith lay open to the Witch-king's assault, but at that moment the forces of Rohan entered the Battle, and the attacking forces were drawn away.

Grond the battering-ram took its name from the Hammer of the Underworld, the mace of Morgoth the first Dark Lord, with which he fought against Fingolfin before the Doors of Angband.