- Classification: Kaijū
- Homeland: Earth
- Choujin Kyoudo: ??
- First Appearance: Manga Chapter 16, Anime Episode 4
Kappatron (カッパトロン) is a Kappa Kaijuu who attacks Tokyo while Natsuko is interviewing Kinnikuman. He speaks in an Osaka dialect. He is ultimately defeated by Terryman because Kinnikuman wasted time reminding Natsuko to take pictures. It could be said that Kappatron played an important role in Terry and Natsuko's relationship, as his rampage provided them with a chance to meet. He was also the first fan submission Kaijū.