Special enemies in Sekaiju no Meikyuu (Etrian Odyssey). A backronym for "Field-on Enemy" in Japanese. Known instead as "Formido Oppugnatura Exsequens" in English, replacing the Engrish with faux Latin.
Unlike regular enemies, they appear in the field and have specific behaviors, like patrolling set patterns or chasing after the player. When first encountered, they are likely to easily wipe out the party; many of the puzzles in the Labyrinth revolve around avoiding encounters with them. If killed, they respawn after 3 in-game days.
In battle, different types of F.O.E have different appearances just like any other enemy, but in the DS era they all appear as a fuzzy orange ball in the field. This led to an association with Kedama from Touhou. This also produced the alternate backronym "Fuzzy Orange Enemy".
Made famous by Iosys's F.O.E. song, "えふおーいーとのそうぐう (F.O.E. to no Souguu)".
