Ballistas

Bahamut, the Volcanic Dragon

 * Needs 60 people to launch
 * Does 9,982,500 damage

Ragnarok, the Ice Elemental

 * Needs 60 people to launch
 * Does 9,075,000 damage

Cronus, The World Hydra

 * Needs 20 people to launch
 * Does 2,680,000 damage

Deathrune Siege

 * Needs 100 people to launch
 * Damage: 1,500 kills