Metron, the Mysterious Space Man - S1.E22

A saucer-shaped spaceship approaches Earth, and heads for Tokyo. It lands on a forested hill not very far from the city. But it is discovered lying harmlessly awkward. Two Unicorn men enter the hatch, and find a creature beamed down on the floor under the fallen control panel. They drag out the creature. It is no human being. It has three eyes. The creature is grateful for being rescued, and offers the men small pills which it claims is space food that would support a man without food for a year. But as soon as they take the pills, they fall stiffened like stone.