Lunar Dragon is an optional boss in the Game Boy Advance port of Final Fantasy IV. It is fought during Rydia's Lunar Trial at the Lunar Ruins. When beaten, the player obtains the Mist Ring (which grants the Blink status to the party when Mist Dragon is summoned), and the Grimoire LD, which, if used as an item, summons the Lunar Mist Dragon to deal 9,999 damage to all enemies. Using up the Grimoire unlocks the trial door again.