Ahriman from FFXI
The Ahriman traditionally appears as a floating creature with a predominant single eye. The appearance of the monster leads to alternative names such as Evil Eye or Float Eye. The word Ahriman is an alternative name of Angra Mainyu, a spiritual foundation in Zoroastrianism, which appeared in Final Fantasy X-2 as a superboss.
Ahriman first appeared in the series as one of the final bosses in Final Fantasy III for the Nintendo. In Final Fantasy IV, an alternate form of Ahriman appears in the final dungeon as a boss. In Final Fantasy X, a monster named One Eye can be created through the Monster Arena. In the Final Fantasy remake Final Fantasy I & II: Dawn of Souls, the Ahriman from Final Fantasy III was selected with the other three Black Crystal Guards as optional bosses in one of the new special dungeons added to the game. Lastly, Ahriman appears as a ghost-like boss in Final Fantasy XII. Ahriman has appeared in all numbered games in the series except II, V, and VIII. They have also appeared in Chocobo's Dungeon 2, Final Fantasy Fables: Chocobo Tales and Itadaki Street Portable. They are featured as a Gummi Ship model in Kingdom Hearts. Alternative names include Buer, Float Eye, Evil Eye, Veteran, etc.