Zetton or Z-Ton is the monster under command of Zettonians. His subtitle Space Dragon (宇宙恐竜) suggest that its proper name should be Zettonian Dragon. Although it was hint that known Zetton is actually cyborg specially design by Zetonians to defeat Ultraman. Said to be "the strongest monster in universe" at time, it's certain that Zettonians are so proud of the monster enough to named it after their home planet.
Zetton resembles a giant humanoid beetle with a glowing yellow streak down his face (in lieu of a mouth) and torso, striped white limbs and black armor skin. The yellow panels on Zetton's chest are actually compound eyes while its "eyes" are two sensory pits, use to emit sonar or radar signals. Zetton's roar is a series of beeps and a low pitched voice that utters "Zet-ton".
Zetton can shoots fireballs, said to be 1-trillion-degree-Celsius, from its mouth and can create a force field which resembles Baltan's. Unlike Baltan's force field, Zetton force field cause Ultraman's Ultra Slash energy saw to shatter upon contact. The force filed is also capable of absorbing Ultarman's Specium Ray, then convert it and shoot back in form of energy wave from its hands, Zetton Final Beam. On top of these abilities, Zetton is also capable of teleportation over short distance. It also has strength that far surpass Ultraman and can break free from his energy binding ring easily.
Zetton appeared after Science Patrol manage to take down the massive force of Zettonian, but the Zettonian mothership release Zetton before it was detonated. Zetton quickly approached the Science Patrol headquarter and battle Ultraman. Despite his best effort, none of Ultraman's atatck has effect on Zetton. In the end, Zetton use its Zetton Final beam to damage Ultraman's vital Colour Timer. With Earth's giant guardian defeated, Zetton continue to destroy the Science Patrol headquarter but eventually destroyed by Earth's new experimental missile.
In other series
Being the first monster to defeat Ultraman, it isn't surpise that other races have replicate Zetton and used in their attempt to conquer Earth. Such attempt including Bat's Zetton II which has its right hand equipped with a napalm launcher. Although Zetton II proved to be as tough as the original, Ultraman Jack managed to destroy it by using his Ultra Hurricane to throw it into the air, then use the Specium Ray to detonate it.
Another Zetton was used by Psycho Baltans against Ultraman Powered, this Zetton has smaller arms and can spread its wings. It got destroyed by three succession shot of Powered's Mega Specium Ray.
In Ultraman Mebius, Human use information gather from the first Zetton to creat a capsule monster. During simulation test, Zetton easily defeat other capsule monster including Earth monster Gudon and copy of Mebius. However, Zetton went out of control due to malfunction and start to destroy GUYS (Guards for UtilitY Situation) taskforce's computer system. The real Mebius transfer himself into the simulation and engage Zetton. Although Mebius is fully aware of its abilities, Zetton is truly a tough opponent. It eventually got defeated as GUYS send in other two capsule monsters, Windam and Mikras, to assist Mebius.
Another variant known as Zetton EX also exist.