Giant's Chest is an enemy in Final Fantasy IV: The After Years exclusive to Final Fantasy IV: The Complete Collection. It is part of the Superboss Lost Babil, and is faced in the second part of the battle alongside Giant's Left Arm and Giant's Head.
The Chest will summon monsters, in order of Dark Grenade, Wild Bat and then Optic Blaster. It will support Dark Grenade by casting Curaja on it so the Dark Grenade does maximum damage when it uses Self Destruct, while the Wild Bat and Optic Blaster are mere annoyances that use the weak Bloodfeast and Beam every turn. If the Chest is killed the Head may begin to use Holy and Laser several times a turn, so the Head should be targeted first. Destroying the Head begins a chain reaction that destroys the Chest and Left Arm.