In the trailers for Marvel Studios’ forthcoming film “The Fantastic Four: First Steps,” Galactus is depicted as a colossal figure, raising questions about whether he is a Celestial. Despite his size and power, Galactus is distinct from the Celestials, although he has the might to challenge one. He is an extraordinary entity who upholds an enduring legacy from past beings. The Marvel Comics Universe explains the universe’s persistent expansion and contraction through a multiversal cycle of creation and destruction. Prior to the current cycle, six complete cycles existed, with Galactus originating in the sixth as a mortal named Galan, a tale recounted in Marvel Comics “Super-Villan Classics” #1.

In the Sixth Cosmos, Galan was part of the Taa-an, an advanced alien race that persisted till their universe’s end. As one of the last beings of the Sixth Cosmos, Galan and his peers chose to plunge into the radiation egg that had annihilated nearly all life. While his companions perished immediately, Galan survived and was chosen by a supreme being named Omnimax to be his heir. Omnimax, once mortal in the Fifth Cosmos and later the Sentience of the Sixth Cosmos, combined his essence with Galactus and used the life force gathered as the Sixth Cosmos’ destroyer of worlds to initiate the Seventh Cosmos, placing Galan in an incubation phase. Emerging from incubation, Galan transformed into Galactus, the all-powerful eater of worlds in the Seventh Cosmos.

Galactus differs from the Celestial beings in the Marvel Universe in terms of origins and goals, although they both wield immense power. The Celestials were the creations of the First Firmament, the first universe (or First Cosmos) that ever existed. They rebelled against him, leading to the birth of the multiverse. Thus, Galactus is linked to the First Firmament as a cosmic being, existing due to the Celestials’ actions. This lineage makes Galactus a unique entity, unlike any Celestial. 

The Celestials are a group/race of beings with their own agenda. They desire to push the bounds of life and the universe by creating new universes and experimenting with life force; for example, they use beings like the Eternals to prime planets for the birth of new Celestials. Unlike the Celestials, Galactus serves a larger purpose in the universe and is, as such, not driven by ambition, allegiance, or morality. As the Devourer of Worlds, Galactus constantly hungers and can only be somewhat satiated by planets that house advanced civilizations. Galactus must eat planets to sustain himself and his hunger is necessary for the maintenance of the universe, but he doesn’t choose planets through anything other than random discovery. Galactus ensures the cycle of life and death continues, and the life forces he has eaten and stored throughout his existence will ensure the creation of the Eighth Cosmos once the Seventh Cosmos comes to a close.