Chocobo's Mysterious Dungeon is a video game made for the Sony PlayStation and Bandai WonderSwan. The game is vaguely linked to the Final Fantasy series by the series' trademark mascot, the Chocobo.
The title character in Chocobo's Mysterious Dungeon is a yellow chocobo named Poulet (プーレPūre, a pun on the Japanese "pureiyā" meaning "player" and the French word "poulet" meaning "chicken"), but the player can rename him.
A moogle, named Atla (アトラAtora), travels with Chocobo to a village. Here, a chocobo villager becomes possessed by an evil crystal after finding it while tiling his field. He kicks Chocobo into a dungeon. Later, Chocobo manages to save the villager from the crystal only to have Atla get possessed by it. Atla is later saved by Chocobo and Chubby Chocobo, who proceed to destroy the crystal. Chocobo and Atla then leave the village.