The Evil Eye, also known as Eye in the NES version, is a miniboss in the original Final Fantasy and its subsequent remakes. The Evil Eye is a skull-type monster, consisting largely of a big head and only one, giant eye. This monster lives in the Cavern of Ice, where it is the Levistone's infamous guardian, and in the Flying Fortress, where it appears as a random encounter.
The Evil Eye in the former area is found one step before the stone and must be battled to obtain the key item. It can be fought as many times as the player's party wants, because it does not disappear from its position after being defeated. The player can move to another adjacent tile, and then return to fight the Evil Eye again for level grinding purposes, as it gives out a considerable amount of experience points upon defeat.
The Evil Eye does not have any specific weaknesses, so attack physically with your Thief/Monk/Warrior; use your highest grade magic to harm it, and heal as necessary. It should not be too hard due to its low HP level, which ensures an easy battle if physical tactics are devised.
In the original Japanese version of Final Fantasy, the Evil Eye greatly resembled a Beholder from Dungeons & Dragons, and was even called Beholder. Outside of Japan and for remakes in all regions, the design and name was severely changed, likely for copyright reasons. The original graphic of the Beholder was kept for the player icon of it in Dissidia Final Fantasy, in all versions of the game.