Grond (Hammer of the Underworld)

Grond, called the Hammer of the Underworld, was Morgoth's mighty mace that he bore when he fought Fingolfin before the doors of Angband. Each time Grond struck the ground it shook the land like a bolt of thunder, creating pits from which smoke and fire erupted. However, Fingolfin evaded these lumbering strokes like a flash of lightning; he only fell when he grew weary and Morgoth was able to "set his left foot upon his neck, and the weight of it was like a fallen hill".

Much later during the Third Age, Sauron constructed a great battering ram, also called "Grond", designed solely to crush through the mighty gates of Minas Tirith. Named after his former master's weapon, this ram, powered by the Witch-king, broke the city gates in four strokes.