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 fired a white goo from his antennae and grew large out of rage. With Toru stuck on among 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. Toru was forced to watched in horror when Leo chopped both of Guiro's antennas, killing the alien in the process. As everybody went to Guiro's dead body, now reduced to human-size, Toru expressed his anger, as the alien's reign of terror was only out of his fright for humans. Gen stepped back from the crowd and transformed into Leo again and revive Guiro by regrowing his antennas. Guiro bid farewell to Toru and left for the outer space.
- Designer: Osawa Tetsuzo
- According to Toru, Guiro likes ice cream and candy and he won't do any harm except if someone attacks him, he just wants to get along with humans.
- Although not physically seen, 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 emit a stream of white foam from his antennas, solidify on the target at contact.
- 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 | Kiraa | Alien Akumania | Ashuran | Sevenger | Taishoh | Alien Atlanta | Alien Mazaras | Specter | Alien Babarue | Black Directive | Silver Bloome | Black Dome | Absorba | Demos | Black Garon | Blizzard | Mayuko | Hungler | Black Terrina | Satan Mora | Nova | Alien Bunyo | Black End|