The Kabuto Yummy is a rhinoceros beetle Yummy created by Uva from a girl named Rie Shiratori, feeding on her supposed desire to become stronger. To that end, while achieving his complete form, the Kabuto Yummy targets Rei's Kendo classmates before Eiji fights him as Kamen Rider OOO Takagoriba to counter the Yummy's hard-armored body. However, during the fight the Kabuto Yummy creates the Kuwagata Yummy from its body in response to Rei's growing desires. With the Kuwagata Yummy's support, the Kabuto Yummy overwhelms Kamen Rider OOO and Ankh until Kamen Rider Birth appears and evens the odds, the two Riders ultimately destroying the Kabuto Yummy with a Cell Burst attack and Tatoba Kick combo attack.
The Kabuto Yummy was voiced by Kenta Miyake.