Buyo Buyo (named after the Japanese onomatopoeia of a squishing noise, can also mean flabby) is an effect NPC that can be found in the deeper part of FC World B, surrounded by four statues. It is an odd, blue creature that doesn't do much of anything. Interacting with it gives the player the Buyo Buyo effect. It reacts normally to the Cat and Knife effects.
- When the Stoplight is used, its sprite changes slightly, with its pupil disappearing creepily.
- In the game's files, there is an unused Buyo Buyo in the game's regular art style. It was used in versions 0.06 and 0.07, where Buyo Buyo appeared in one of the houses at the Barracks Settlement instead. This means that it is the only characters other than Madotsuki and the Pirori who has an appearance in both art styles.
- Also unused are some flabby-looking sprites of Buyo Buyo. These were used in versions 0.08 and 0.09, where the Seahorse is sucking Buyo Buyo dry!