Alien Wyaan was a Seijin that appeared in episode 2 of Ultraseven.
Subtitle: Organisms X (生物X, Seibutsu X)
- Height: 1.8 - 150 meters
- Weight: 100 kg - 13,000 tons
- Metal Shell: Alien Wyaan has a metallic shell made of Tilsonite 808, a metal so thick Ultraseven can not see through it or sense activity inside. This shell contains an organism that Alien Wyaan can morph into, and there is a smaller replica that mimics what happens to the larger one.
- Blood Drain: Alien Wyaan can drain the blood from his prey by grabbing them. Anything that survives this attack will turn into a Alien Wyaan as well.
- Growth: Alien Wyaan can grow from human size to over 492 feet and 13,000 tons.
- Stun Ray: Alien Wyaan can release a green ray from his arms that can stun enemies.
An alien plant covered with countless thorns, Wyaan uses two extraterrestrial Tilsonite 808 rocks to disguise himself as Ishiguro, a crew member of Space Station V3 who has just returned to Earth. Under the cover of night, Wyaan reverts to his true form and begins attacking humans by sending blood-sucking tentacles down the streets. In turn, the victims become Wyaan-type monsters themselves, and spread the vampire-like epidemic across the city.
When his Tilsonite 808 rocks are destroyed (revealing that they contain alien machinery and the real Ishiguro within), Wyaan's cover is blown, which then forces him to go through a gruesome transformation while on a train in the middle of a tunnel. He then takes on giant size and battles Ultraseven until he's cut completely in half by his Eye Slugger. Ultraseven then destroyed the halves with his Emerium Ray.
- In theTurner Network Television dubbed version, he and his brethren were called Violim Shrubs.