The Catapult was a projectile weapon that shot debris and rocks against the enemy. The Orcs of Sauron's army used catapults during the Siege of Gondor to attack the city of Minas Tirith. Among the objects utilized were great stones, the heads of fallen Gondorian soldiers, and fireballs.
Portrayal in adaptations
In Peter Jackson's The Lord of the Rings: The Return of the King, catapults are seen during the Siege of Gondor at Minas Tirith. Gothmog initially orders Guritz to fire catapults with the heads of fallen Gondorian soldiers. Later, Trolls use fire catapults to siege other levels of the city.