Costume is a status effect in Final Fantasy XI. Costumes will always change the appearance of the character, and in their most basic form, they are a festive status effect granted by certain items. There are a few places in the game where a costume status will do additional things. This includes the costume in Mamook, which turns a player into a Mamool Ja but also inflicts a Poison upon the player, which the player voluntarily has to obtain. The Poroggo special attacks like Frog Song that turn a player into a frog, but is also accompanied by a Charm effect.