The Piranha Yummy are a school of Yummy created by Mezool by using the a Cell Medal on the shopaholic Haruka Yamano, one of Hina Izumi's classmates in fashion college. Hatching from their egg-like form, the vast number of Piranha Yummy are countered by Kamen Rider OOO assuming Gatakiriba Combo to even the odds before the Yummy gather into a larger form that he destroys from the inside out with the Gatakiriba Kick. Another batch of Piranha Yummy are later created from a con artist while Eiji and Ankh with preoccupied with the Siam-Neko Yummy and Uva's Waste Yummy, succeeding in their purpose before being fed on by the Greeed.
