Muffy is a teenage Flip-Flopian that lives in Flipside. She is very optimistic girl that believes life should be short and sweet. After the defeat of Super Dimentio, Muffy will mention that she spent all of her coins at the Flipside Arcade as she thought the world was ending.
- Muffy's counterpart of Flopside is Lucy. Oddly, Muffy's name is Lucy in the PAL region while Lucy is called "Lacy."