Giygas is an antagonist from the Mother series of video games released by Nintendo
Giygas was an alien found by a couple named George and Maria, who took him in, and subsequenntly captured by Giygas's race, forcing them to raise him (though they lovingly did so as if he were truly their child) until he was mature. George set the trigger to spread the aliens' power of PSI, a strong, psychokinetic power, to Earth. Giygas was instructed by his race to make sure that PSI will not flourish on earth, even if he has to destroy the entire planet.
During the events of Mother, the biological grandson of George and Maria: Ninten, sets out on a journey to stop Giygas, learning parts of a song that was sung to Giygas as a lullabye in his childhood by Maria to gain the strength to do so. During the Battle, Ninten and his friends: Ana and Loid sing the song, thereby weakening Giygas so they could defeat him.
In EarthBound, Giygas has become physically unstable to the point where his new servant, Pokey Minch, who was also the neighbor of the current protagonist, must seal him in a device called the Devil's Machine to keep him intact to plan for the apocalypse, and as he does so, a small winged arthropod named Buzz Buzz travels back in time ten years to warn a boy named Ness of Giygas and his intent. Like Ninten, he must learn 8 short melodies to make a small, lullabye-like song not entirely different in function or notes from the song Ninten learned. Travelling with members of a party he built over time, eventually consisting of himself, a telepathic girl named Paula, a child prodigy named Jeff and finally a disciplined Dalaam warrior prince named Poo, they travel with all melodies back in time to the cave of the past to defeat Giygas, only to find he is protected heavily by the Devil's machine, and aided by a heavily armed Pokey. Finding that Damaging Giygas was going nowhere, they attack Pokey to the desperate point of shutting off the Devil's Machine, which destroyed Giygas's unstable body, destroying his mind and killing him by destroying his body and releasing his ghost, a swirling red vortex of pure energy and evil with an indescribable attack, becoming more strong than the children can counter with all the PSI or weapons they can utilize, forcing Paula to pray to the citizn's of Earth for help. It proves effective, the prayers damaging Giygas so heavily that his base psychological essence is destroyed.