Space Gyaos is a genetically-engineered extraterrestrial version of the Earth kaiju, Gyaos. It's overall similar in appearance, but has silver-colored skin. Unlike the Gyaos on Earth, Space Gyaos is not affected by sunlight (as in space, it would be impossible for him to avoid the light). It appears as a minor antagonist in the Showa era Gamera movie, Gamera vs. Guiron.
A flock of the creatures attacked the planet Terra - a planet in our solar system which humanity had not yet discovered - but were repelled continuously by the Terran's guardian monster Guiron.
When two young boys accidentally end up on Terra, they watch as Guiron battles a Space Gyaos. Space Gyaos fired a sonic beam from its mouth - only for it to deflect off Guiron's blade and slice off Space Gyaos' right foot. Initially flying off, Space Gyaos returned in the hope of destroying Guiron in an aerial attack.
However, Guiron anticipated the move and sliced off Space Gyaos' wing. Guiron then proceeded to slice off the Space Gyaos' other wing, decapitate the injured beast and slice up its body.
After Gamera had traveled from Earth to Terra and killed Gurion - recovering the two boys and returning them home in the process - Terra was seemingly abandoned to the Space Gyaos, although none were seen on Terra when Guiron was revived by the evil Zanon aliens (who were trying to take over Earth) to fight Gamera.
Gamera vs. Guiron - Movie