Gamera Vs Gyaos is the third movie in the original series and it was released March 15 1967. In Japan it was called Giant Monster Midair Battle: Gamera Versus Gyaos. It was first released in the US by AIP-TV as Return Of The Giant Monsters and the Sandy Frank version was released in the 1970's Gamera vs Gaos. It was that Sandy Frank version that was one of the five Gamera films poked in the ass by the guys at Mystery Science Theater 3000.
Men are working on a highway through the hills near a small village. The villagers aren't happy with the new road. They protest and sabotage the work. A helicopter is downed by a strange beam emiting out of a glowing area in the hills near the construction site. When a reporter comes to check it out he's surprised by a giant monster. That surprise doesn't last too long, he's eaten. A little kid had helped him find a path to the glowing hillside and he's was still there when Gamera arrives. Don't worry he's saved by the giant turtle. The two monsters fight and Gamera gets hurt. Gyoas has a beam that can slice though helicopters, airplanes and Gameras. The giant turtle retreats to the sea to recover after his arm is nearly cut off. The new monster is christened Gyaos by the little boy who figures prominently in the story. Gyaos damages stuff and delivers mayhem to the villagers and the road crew. Most everyone evacuates and the military moves in to blast the beast. It doesn't do much good and Gyaos moves to the city. They find out that sunlight hurts Gyaos so they set up a trap. It's a synthetic blood filled fountain that spins. Unfortunately the power station fails and the fountain stops. Gyaos smashes up some more real estate. Gamera finally kicks his ass in the last act.
Gamera vs Viras is the 4th of the series and it was released March 20 1968. It's called Gamera Versus Space Monster Viras in Japan. It was first out in the US under the title Destroy All Planets. It wasn't picked up by Sandy Frank in the 1970's and didn't get used on MST3K.
Gamera happens across an alien spaceship while he's cruising through space. I guess once you get a taste of space travel it's hard to give that up. I gues Gamera thinks the aliens are too close to earth and he gets in their way, There's a fight and before they are destroyed the aliens send back a warning to the home planet. Back on earth some boy scouts are having a jamboree. There's a minisubmarine to look at and two of the boys get a chance to try it out. They find Gamera under the water just before the aliens show up to scan the giant turtle. The aliens learn Gamera likes kids and they kidnap the two scouts to get a hold over him. After installing a device on the giant turtle's head the aliens are in Gamera's driving seat. They take him on an orgy of destruction. The alien bastards smash a dam, some buildings, toss military vehicles around, and flatten anything that gets in their way. Back on the ship the always prepared boy scouts screw up the alien equipment and free Gamera. He bashes the ship and brings it to the ground. The aliens all merge into a giant monster with three points on it's head and some tentacles below the waist. Gamera gets beaten pretty badly but he rises to the occation and beats that monster by draggin' his ass into space where he turns into a monstersicle. The earth is saved and the boy scouts give Gamera a big rousing sayonara before the credits roll.
There's a big change in the story with kids being more of the focus. Neither is a great film and they really suffer in the US versions. The Japanese versions are better to watch. The movies are nice widescreen copies with good color and nice sound. I still enjoy these but they just aren't something I'd want to watch that often as the better Japanese monster movies that I watched arlier this year. If you're only going to see one or two of the series stick with the first two.