- Name: Ukon (ウコン)
- Classification: Kaijū/Robot
- Homeland: Roots Island
- First Appearance: Roots Island Arc Manga Chapter 26
Ukon (ウコン) is an ape Kaijuu who appears as the main antagonist during the Roots Island story. He turns out to actually be a robot piloted by Kinkotsuman and Iwao. He initially defeats Kinnikuman and takes over Roots Island, but Kinnikuman returns to fight him again. He is eventually destroyed by Mammora, and when Kinkotsuman and Iwao crawl out of the robot head Kinnikuman yells at them and scares them away.