Giygas

Giygas, also known as Giegue, is the main antagonist in the first two Mother games, Mother, and EarthBound. In both games he is an alien being of immense power.

Mother
As explained in Mother, Giygas was originally an alien named Giegue (for more information, please see the name section at the bottom.) who cared for two people named George and Maria as they were held captive by aliens that had abducted them. Giegue held immense psychic power, known as PSI. After being let go by the aliens, George began to research it and spread the research. Giegue took offense to this and invaded Earth several decades later.

George's great-grandson, Ninten, can use PSI because of George. When his home is invaded by angry ghosts, Ninten sets out to find out why. Ninten, along with the rest of his party, come into blows with Giegue and his mind-controlling aliens throughout the game. Along the game, they learns pieces to a song that will weaken Giegue. In the final battle, Giegue attacks the party. His attacks are inexplicable. After a certain amount of time has passed, the party will be able to use the Sing command. After singing eleven times, Giegue will admit defeat and leave. As he leaves in his mothership, he vows revenge on Ninten.

EarthBound
At the beginning of EarthBound, a young boy named Ness and his neighbors Porky and Picky investigate a meteor that has crashed in Onett. In the meteor is insectoid, time traveling alien Buzz Buzz. Buzz Buzz warns of a dismal future where alien despot Giygas rules all. He also warns of the Chosen Four who will stop him. Shortly after, they are attacked by Starman Junior, one of Giygas' henchman. Buzz gives Ness the Sound Stone to record the Eight Melodies. While never explicitly stated, these may be the same melodies as in Mother.

Giygas' evil influences wild animals and humans to do foul things. Early in the game, a statue called the Evil Mani Mani that inspires evil. The Happy Happy Cult is inspired to do evil things by it, including kidnapping Paula. Later, it inspired Monotoli to be a corrupt mayor.

Through the game, Pokey becomes increasingly corrupt. He enjoys manipulating people. Towards the end of the game, Pokey travels hundreds of years back in time to meet with Giygas. He uses a machine called the Devil's Machine, which helps contain Giygas' immesuarable power. By this point, Giygas' power has destroyed his physical body, leaving him a dissembodied being. He also lacks true sentience. Porky says "he is the evil power.". During the final battle, Paula calls on the people of Earth to help defeat Giygas. Eventually, by using the prayer command, Giygas is defeated.

Name
In both Japanese releases, Motehr and Mother 2, Giygas is called Gyiyg. Although it was never released, NOA did translate Mother into English, as Earth Bound (two words). In it, Giygas is called Giegue. In EarthBound he is called Giygas.