Catastrophe, also known as Catastroph, is a boss and one of the Demons of the Rift in Final Fantasy V. It is blocking the exit of the dungeon in the Interdimensional Castle, and must be fought to proceed.
Casting Float and Reflect on any party member should cause him to use nothing but Gravity 100, which will be reflected, and ensure victory.
Catastrophe appears as the second encounter in the game’s first raid tier, Omega Detascape. He maintains some of his original appearance’s attacks, such as Evil Sphere, a tank buster. His 100 Gs brings any party members who are currently floating to the ground. This version also has the opposite attack called -100 Gs which will launch the party into the air.
A catastrophe is "an event causing great and often sudden damage or suffering."