An alien from Planet Metron who plans to intrude Earth, also known as "Hallucination Alien".
He has a long red face rimmed in yellow, a blue body and fin-like hands.
As a beginning point in the invasion of Earth, Alien Metron disguised as a man in black suit living in Kitagawa-cho. He plans to extinct humans by making them fight each other, spreading cigarettes that make humans who smoke them aggressive.

When Dan Moroboshi (a.k.a Ultraseven) detected Alien Metron's base, he invited Dan to sit down and talk. But it was a trick planned by Alien Metron, and the base was a flying saucer in disguise. As soon as Dan was off his guard, Alien Metron flew the saucer out into space aiming to expel Dan.
However, once the saucer was soon shot down by Ultra Hawk 1, Dan escaped and transformed into Ultraseven.
Alien Metron also became huge and fought, but soon realized that he was no match for Ultraseven. He tried to escape, but was cut in half by Ultraseven's Eye Slugger and exploded to bits by the fatal shot of the Emerium Beam.
(This story is from ULTRASEVEN)