Virasians

Virasians are a race of squid-like aliens from the Planet Viras created by Daiei that first appeared in the 1968 Gamera film, Gamera vs. Viras.

Appearance
Most of the time, Virasians appear under human disguises to blend into society. However, they can be told apart from other humans by the fact that their eyes glow a faint yellow when they are in darker areas, as this benefits their eyesight. When their disguises are lost, all Virasians resemble smaller versions of their vanguard Kaiju, Viras.

Gamera vs. Viras
The Virasians first appear aboard their spaceship, which is approaching Earth, being hear but not seen. Gamera attacks the spaceship and sets it on fire. Before the ship explodes, the Virasians manage to send a distress signal to their home planet, and more Virasians travel to Earth. All but one change into human disguises, and later take two Japanese boy scouts hostage after learning of Gamera's love for children. This allows them to take control of Gamera through mind control. After Gamera breaks free of the Mind Control, the rest of the Virasians shed their human disguises, and all decide to fuse into their collective form, Viras.