Viras is an alien Kaiju featured as the main antagonist in Gamera's fourth film, 1968's Gamera vs. Viras, known as "Destroy all Planets". Viras was the leader of an alien invasion, set upon conquering the Earth. An earlier attempt by his kind was easily thwarted by Gamera, so Viras employed a mind probe to discover Gamera's weaknesses. Viras discovered Gamera's kindness to children, and exploited it by kidnapping two Boy Scouts and using them as hostages, coercing Gamera to get into perfect position for the launching of the mind-control device. Gamera was then made to rampage through Japan, the targets being the Okomasashi Dam and eventually Tokyo. When the two boys were able to escape, Gamera attacked, and Viras fused with his crew members to become a giant. After a fierce battle, Viras was presumed dead when Gamera flew with him up into space, freezing him to death in the icecold, and then dropping him to his fate.
Viras' main attack is his constricting tentacles on both his body and head. He posesses a sharp beak and can make the tentacles on his head form into a spear-like point. He has no projectile weapons to speak of. He also has the ability to breath underwater and the ability to talk through telepathy.
Viras is susceptible to being frozen. Gamera kills him by flying him up in to the atmosphere and freezing him solid.
Like many of his fellow "Showa" era monsters, Viras has not appeared in any movies since his initial movie debut, save for a stock footage appearance in the film Gamera: Super Monster. However, he made an appearance in the short-lived Gamera comic series by Dark Horse that was based on the Heisei Gamera movies. In this series, he was the product of experimentation with Gyaos DNA. He'd eventually face off against Gamera amidst the streets of Paris, France. In said comic series he looked relatively the same, except for more Octopus/Squid-like features. Viras also appeared (along with other "Showa" era Gamera monsters) in an episode of the children's cartoon Franklin. In the episode, Franklin is afraid to go into his shell at night because it's dark, and his fear is manifested as ghosts of the various Gamera monsters including Viras that come out of his shell.