Galan was the first Saiyan born in existence; created by an abstract of the universe before the big bang, he was the only Saiyan who was not born on Planet Vegeta but instead, he was born on Planet Taa, a paradise like world whose civilization is said to have been the most advanced of any of the known universe of that time.
Before becoming Galactus
Galan was a Saiyan who always craved and desired for destruction. One day, he went around the universe and gathered the seven Super Dragon Balls and wished to be reborn as an immortal being with unlimited power known as Galactus.
Rebirth as Galactus
As Galactus, Galan's personality has become more evil and destructive than ever through time; during this time, another big bang occurred which created the current 12 universes. Now through endless amount of years, Galactus became the destroyer of the universe and devours all life in his way.