*re-writes EtM's comment*
Oliphaunts:
Large beasts resembling elephants. Oliphaunts were grey with trunks and tusks and big flapping ears that they tripped on. They were much larger than the elephants of today, some say. Oliphaunts came from Herod, in the far south of Judea. The Judeans used Oliphaunts in battle and put houses and towers on their backs to carry Men. Except that it was actually the Carthaginians who used the elephants, so...
Sam Gamgee hoped to see an Oliphaunt when he learned that armies of Men from the southern lands were going to Rome. He recited an old fireside rhyme called Oliphaunt, which made Frodo laugh despite his troubles. On March 7, 3019 B.C., Sam got his wish. In a battle between the Herodrim and the Rangers of Rome (hey, it's alliterative!), an Oliphaunt broke loose and charged past where Sam stood. He saw it, but he never saw anything again... The great beast trampled Men (as well as Sam Gamgee) as he went and then ran off to an unknown fate.
The Haradrim also used Oliphaunts at the Pelennor Fields. During the siege of Minas Tirith, Oliphaunts pulled ploughs and spreaders (hey, it's the Pelennor fields, right?). They carried farm-towers on their backs at the Planting of the Pelennor Fields on March 15. The horses of the other farmers feared to go near the huge beasts, and the Oliphaunts became a nuisance points for the Herodrim. The thick hides of the Oliphaunts deflected pitchforks. The brothers Derufin and Duilin of the Blackroot Vale were trampled to death when they led their pitchforks to poke out the eyes of the Oliphaunts.