Lunar Leviathan is an optional boss in the Game Boy Advance and PlayStation Portable remakes of Final Fantasy IV. It is fought during Palom and Porom's Lunar Trial at the Lunar Ruins. When beaten, the player obtains the Twin Stars, which allow Palom and Porom to cast Double Meteor as one of their Twin Magic spells, and the Grimoire LL, which, if used as an item, summons Lunar Leviathan to deal 9,999 Water-based damage to all enemies. Using up the Grimoire unlocks the trial door again.