Unknown Alien Overlord

Unknown Alien Overlord is a mysterious villain who appears although not physically in Godzilla King of The Monsters. He doesn't have a real name which is why the wiki calls him this title.

He's the true antagonist of both films although he never appeared physically in the first one or was ever mentioned in the second one.

Before Godzilla King of The Monsters
Long long ago, an evil alien who's name is unknown, terrorized Earth with his pet monster King Ghidorah. The Humans awakens Mothra and she puts Ghidorah into a deep slumber, as well is destroying the alien and his spaceship.

Unknown her her, the alien's soul possesses the peaceful monster Anguirus, which makes him go berserk.

Mothra battles and puts him to sleep as well, leaving the alien powerless

for all the years to come.

Godzilla King of The Monsters
The Unknown Alien Overlord awakens the Robotic alien monster Zorgo on his home planet through telekinesis, summoning him to Earth.

When Zorgo's ship arrived on Earth and attacks a city, the alien overlord makes his presence known through communicating to the Military while Person 1 discussed the Oxygen Destroyer.

Godzilla eventually battles and destroys Zorgo, delaying the alien's revenge.

Godzilla Raids Again
The Unknown Alien Overlord manages to awaken King Ghidorah and get's him to rampage.

As well as waking up Anguirus, causing him to rampage as well.

When Godzilla showed up and begins to battle Ghidorah, the alien gets Anguirus to aid him in the fight and ends up getting pushed into an iceberg by Godzilla, causing Godzilla and Anguirus to fall into it, becoming trapped.

The iceberg drifts off to sea, delaying the alien's revenge possibly forever.