Subtitle: Space Star Beast (宇宙星獣 Uchū Boshi-jū)
Coming to Earth without the intention of an invader, Guiro hid himself in the Monster Park, a section of an amusement park where monsters defeated by previous Ultras were the theme for attractions. One day, he met Toru and hypnotized the boy to give him an ice cream. While Gen and his friends happily watched the monster attractions, he detected that Guiro as an alien, since he was seen eating an ice cream compared to other costume monsters and Gen's Ultra senses. Guiro and Toru ran away from Gen, but he successfully tailed them with a truck. Guiro shot foam from his antennae and grew to his full size in a fit of rage. With Toru holding on to Guiro's scales, Gen transformed into Leo and fought him. Despite both Leo and Guiro's strength being matched, the alien made his escape.
Later, MAC crews arrived at the amusement park, where Guiro and a hypnotized Toru played in a Carousel. Despite MAC aiming for Guiro, however, the alien escaped to his own realm. Toru was sent to a hospital for treatment but the alien appeared to play with him again, and took him to his realm. While Dan was busy training Gen, they were alerted that Toru had disappeared from his ward. At night, Guiro, in his giant form, was detected in a city and MAC was sent to attack him, unaware that Toru was stuck among Guiro's scales again. After Gen finished his training, he transformed into Leo and attacked Guiro. However, Toru ordered him to stop, not wanting his new friend to die. Guiro later fired his sticky foam to Leo but the Ultra spun himself in the midair to escape from it. With firepower from MAC's fighter jets to distract the alien, Leo kicked Guiro on the back, freeing Toru from his scales and cough the boy just in time to put him down safety.
The battle between Leo and Guiro then continued, as the duo proceeded to duel across the amusement park. In the battle's climactic moment, Leo severed Guiro's antennae during a forward flip, instantly killing the alien, whose giant form dissolved away to leave his body lying lifeless on the floor. Mourning Guiro, Toru exclaimed in anger and sorrow about what had happened, as the alien's reign of terror was only out of his fright for humans. Deciding to set things right, Gen quickly stepped back from the crowd to transform into Leo out of MAC's sight, then restored Guiro's antennae, bringing him back to life. Bidding everyone farewell, Guiro then set off for outer space to begin the journey back to his home planet.
- Designer: Osawa Tetsuzo
- According to Toru, Guiro likes ice cream and candy and he will not do any harm unless someone attacks him; he just wants to get along with humans.
- Guiro is one of the Kaiju that makes up Belyudra's body in Mega Monster Battle: Ultra Galaxy Legends The Movie.
- This is strange considering he was revived and spared. It could have been another Guiro.
- Height: 2.1 ~ 59 m
- Weight: 90 kg ~ 25,000 t
- Origin: Planet Guiro
- Weakness: He will die if his antennas are chopped off.
- Powers and Weapons
- Warm Shower: Guiro can shoot a soap-like foam from his antennae that gradually solidifies upon contact with a target.
- Hypnosis: Guiro can perform a weak hypnosis on a target.
- Teleportation: When needed, Guiro can teleport long distances.
- Realm: Guiro can create his own realm where it also allow its residence to levitate on their own.
- Size Change: Guiro can change his size from that of a human’s to that of a giant monster.
|Ultraman Leo Kaiju|
|Giras Brothers | Alien Magma | Alien Tsuruk | Kanedoras | Alien Karly | Kendoros | Vekira | Guiro | Ron | Alien Kettle | Bango | Alien Vibe | Antales | Alien Flip | Alien Atler | Alien Wolf | Bat Girl | Batton | Alien Boze | Bock | Dogyuh | Alien Alpha | Northsatan | Garon | Littre | Alien Coro | Renbolar | Carolyn | Alien Sarin Dodole | Gamerot | Alien Clean | Satan Beetle | Pressure | Oni-on | Planet Apple Chicken | Alien Paradai | King Paradai | Uriy | Uringa | Alien Magma II | Rolan | Alien Virmin | White Flower Spirit | Princess Kaguya | Kirara | Alien Akumania | Ashuran | Sevenger | Taishoh | Alien Atlanta | Alien Mazaras | Specter | Alien Babarue | Black Directive | Black Star | Silverbloome | Black Dome | Absorba | Demos | Black Garon | Blizzard | Mayuko | Hungler | Black Terrina | Satan Mora | Nova | Alien Bunyo | Black End|