|First appearance:||Ultraseven Episode 35: "Shudder on the Moon" (1968)|
Beryudora (Body Part)
Subtitle: Moon Monster (月怪獣 Tsuki Kaijū?)
- Height: 63 m
- Weight: 75,000 t
- Origin: Moon desert
After Alien Zamppa failed to kill TDF member Kurata and Kiriyama, he sent Petero to do the job after his death. The monster tried to destroy their ships but forunately Dan transformed into Ultraseven and fight him. Petero was able to overpower Ultraseven thanks to the low temperature of the moon and the Ultra was cut from the sun until a meteorite crashed, emitting an explosion which Ultraseven used it to charge himself and finally kill the monster with Wide Shot.
- Petero's body is 80% water, 20% more than humans.
- Suit actor: Kunio Suzuki
- Although not physically seen, Petero is one of the monster that makes up Beryudora's Left Arm in Mega Monster Battle: Ultra Galaxy Legend The Movie.
- Petero's name was inspired by Saint Peter, one of the Twelve Apostles of Jesus Christ, leaders of the early Christian Church. Similarly, Eiji Tsuburaya, the founder of the Ultra Series was a convert to Roman Catholicism.
Powers and Weapons
- Adaption: Petero can survive in airless environments like the moon as well as very low temperatures. Through these adaptations, Petero is able to generate the water and oxygen required for his techniques to work.
- Eye Blasts: Petero can emit red energy blasts from his eye that are presumably filled with oxygen, allowing them to cause explosions in airless environments such as the moon.
- High Pressure Water Hose: From next to his eye, Petero can fire a powerful jet of high pressure water, capable of forcing opponents back. Given that his body is 80% water, he can use this ability for long periods of time without it harming him in any way.