Cocobusi is a non-playable character in Final Fantasy XIV and the youngest of the six brothers—Cocobuki, Cocobygo, Cocobani, Cocobezi and Cocoboha. Due to his lack of thaumaturgy skills, Cocobusi is the only one of the brothers who does not share the joint position of Guildmaster of the Thaumaturges' Guild.
Cocobusi aspires to become a thaumaturge like his brothers, but his low aetheric capacity makes this impossible. Cocobusi has joined the Alchemists' Guild to alchemically enhance his natural potential for arcane manipulation, but his brothers avoid giving him false hope and refuse to accept him for training.
Cocobusi is infuriated to learn his brothers are training another novice instead of him. During the Warrior of Light's trial consisting of tracking down the Alacran thieves and destroying the stolen cursed artifact known as Mormo's urn, Cocobusi follows them. As he is about to destroy the urn, the voice of the voidsent Mormo offers Cocobusi power and Cocobusi accepts. Upon opening the lid, Mormo possesses Cocobusi and begins impersonating him. Mormo begins to attack thaumaturges and drain their vitalities to death, becoming known as the "Mageslayer".
After discovering that the Mageslayer is Cocobusi possessed, Cocobuki studies the Book of Mormo in hopes of finding a reversal method. After locating Mormo, Cocobuki offers to have his aetheric energy drained so that the voidsent can get a physical form and leave Cocobusi's body. Once this is done, the Warrior of Light and the other brothers defeat the succubus.