Galactus

Galactus (The Devourer of Worlds, the Third Force of the Universe) was the only survivor of the end of the universe which existed before the current universe. As Galactus' universe died he became a cosmic entity. His only chance to survive was to eat entire planets. Some individuals, in order to save their planets from destruction, agreed to serve Galactus in various roles. Some examples of these servants were Silver Surfer, Terrax, Firelord, Air-Walker, Nova, Morg and Red Shift.