Roly-poly Surprises - S1.E6

As a new student named Goro Goro enters Harumi's class, various people, including Harumi and Kappaeru, find themselves inflated into a blimp-like form with an insatiable appetite, with anything they touch also becoming fat. As the Yokai patrol lure out Goro Goro, whose real identity is a Yokai named Fukurashiko, they are ambushed by Enpi and turned fat as well. They end up bouncing all over the world, eventaully ending up on the moon, where Enma, Yukiko and Enpi, who was also made fat, simultaneously kill Fukurashiko, returning everyone to normal.