Original is a group of specially bred fiends from Final Fantasy X. Typically more powerful than Area Conquest and Species Conquest fiends, they easily KO a party that has no trouble with the storyline bosses, and as such can be regarded as superbosses. Unlike most superbosses, however, they can be fought as often as the player desires, and offer substantial rewards for unlocking them and for defeating them in battle. To unlock the Original monsters certain requirements need to be fulfilled.
All Original Creation monsters (excluding Neslug) drop equipment that provide a 6% critical hit chance bonus instead of the usual 3% (this is relevant to weapons and armor pieces, but only to attacks that deal physical damage). With the exception of Nemesis, all Original Creations have the Gambler's Spirit item as a common steal, making them an excellent source for farming items for mixes like Trio of 9999 and Hyper Mighty G.
- Earth Eater - Breed at least 2 fiends in Area Conquest.
- Greater Sphere - Breed at least 2 fiends in Species Conquest.
- Catastrophe - Breed at least 6 fiends in Area Conquest.
- Th'uban - Breed at least 6 fiends in Species Conquest.
- Neslug - Capture at least 1 of every fiend throughout Spira.
- Ultima Buster - Capture at least 5 of every fiend throughout Spira.
- Shinryu - Capture at least 2 of every underwater fiend in the Mt. Gagazet cavern.
- Nemesis - Capture 10 of every fiend throughout Spira and defeat all other Original, Area Conquest, and Species Conquest monsters.
The following rewards are given once each Original monster is available to challenge:
- Earth Eater - Three Stars x60
- Greater Sphere - Supreme Gem x60
- Catastrophe - Door to Tomorrow x99
- Th'uban - Gambler's Spirit x99
- Neslug - Winning Formula x99
- Ultima Buster - Dark Matter x99
- Shinryu - Megalixir x30
- Nemesis - Master Sphere x10