The Ghast, also known as the GEIST in the Nintendo Entertainment System] version, is an enemy in the original Final Fantasy. Its attacks may cause Paralysis to party members that it hits, so it is advised to attack all Ghasts physically before a powerful member is paralyzed. As an undead enemy, it is susceptible to Fire-elemental attacks and Dia spells.
It commonly appears near the towns of Melmond and Elfheim and inside the Cavern of Earth and the Cavern of Ice; in their later appearances, they are famous for being dangerous (and frustrating) due to their tendency to attack in large, chain-paralyzing packs.
Geist is a German word. Depending on context it can be translated as the English words mind, spirit, or ghost, covering the semantic field of these three English nouns.