Galactus is an all-powerful cosmic entity that has regularly threatened the heroes of the Marvel Comics multiverse. A colossal-sized humanoid being wielding the Power Cosmic, Galactus' existence seems to revolve solely around self-preservation, usually at the cost of lesser beings. Labelled as a god of destruction by many alien cultures, he travels the stars seeking out planets to feed upon.
Galactus is the sole survivor of the universe that existed prior to the current universe. Originally Galactus was a humanoid named Galan, who was born on the 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.
However, this universe was in its final stages of collapse. Originally, like all universes in the Multiverse, this universe had been a "Cosmic Egg"; a primal sphere of disorganized, dense, compact primordial matter. The sphere underwent a "Big Bang," an explosion that hurled the matter outwards, where much of it eventually condensed into stars and planets. This universe expanded in size for billions of years, and then contracted, undergoing a "crunch" over the following billions of years. All of the matter of that universe was plunging towards a central point, where it was collapsing into a new "Cosmic Egg." Taa's civilization was one of the last still in existence. Lethal radiation caused by the "Big Crunch" this universe was experiencing was wiping out all life across the universe. Galan, a space explorer, was dispatched to travel through the cosmos to find a means of saving Taa, but he found none. The radiation eventually killed off all but a tiny fraction of the population of Taa. Knowing their deaths were inevitable, Galan proposed to the remaining survivors that they die gloriously by piloting one of their starships directly into the heart of the "Cosmic Egg." As the starship containing Galan and his fellow survivors approached the focal point of the Big Crunch, the heat and radiation killed all the passengers except Galan, who strangely found himself filled with new energy.
At the moment Galan's universe met its end, the Phoenix Force amassed the positive emotions of all living beings in the cosmos to preserve them from eternal damnation, enabling the Sentience of the Universe — the previous universe's equivalent to Eternity — to meet with Galan.Within the "Cosmic Egg" the Sentience of the Universe revealed itself to Galan and informed him that though they both would die in the final moments of the universe, they would both survive through a joint heir born into the next universe. The Sentience of the Universe let the mortal Galan gestate within it, and thus Galactus, the devourer of worlds, was conceived.
Eventually the "Cosmic Egg" underwent another "Big Bang," thus creating the current universe. Eternity and Death, the ethereal embodiments of the new universe, were created in this "Big Bang," and the newborn Galactus was simultaneously hurled outward in his recreated starship.
The nascent Galactus drifted in his starship for eons as life began to come into existence in the universe, including the races that would give rise to the Elders of the Universe. Eventually the nascent Galactus's starship was sighted by Ecce of the Watchers, an ancient species who possess vast psionic and energy manipulation powers who had undertaken the task of observing the events of the universe. Ecce drew the starship down to his planet to study it. There he learned that the being within it had power beyond comprehension and would eventually be forced to consume entire worlds to satiate his hunger for life-sustaining energy. Realizing the danger the nascent Galactus posed to the cosmos, this Watcher considered destroying the entity; who was still vulnerable due to his metamorphic state; but instead decided to abide by the Watchers' oath of non-interference, and let the nascent Galactus depart in his starship. Although over time the Watcher race has come to understand that Galactus is an intrinsic and necessary component to the natural order of the cosmos, Ecce has expressed guilt over his decision those billions of years ago and feels partially responsible for the destruction Galactus has caused since.
The nascent Galactus employed his vastly limitless strength and power and created a suit of armour to help him regulate his raging internal energies. He then transformed the starship of Galan into a kind of incubation chamber, where Galactus spent thousands upon thousands of years evolving into his current form. Finally, the incubation ship drifted into orbit around the inhabited planet Archeopia. The Archeopians themselves did not disturb the strange ship, but years later a marauding space fleet, nearing Archeopia and thinking Galactus's ship to be a weapon, attacked it.
Galactus, with his metamorphosis complete, emerged and with a gesture destroyed the invading fleet. Galactus, realizing his uncontrollable hunger for energy, turned his attention upon the energy-rich Archeopia below. Galactus immediately consumed the life energies of the Archeopia, only a small fleet of Archeopian ships managed to escape the planet in time. (The Archeopian race would later be fully exterminated by the living planet Ego).
Since consuming Archeopia, Galactus has travelled across the stars seeking out new worlds to satisfy his endless hunger. At first, he only targeted planets which did not support sentient life, but over time he found that the intervals between his feedings were becoming shorter and has since separated himself from any and all compassion that would otherwise prevent him from setting his sights on populated worlds. Galactus has consumed an unknown number of worlds throughout the eons, including inhabited planets. He has made several attempts to feed on Earth, but has been forced to spare it thanks to the efforts of Earth's various heroes and, on occasion, has consumed the life-energy of extraterrestrial beings in lieu.
Galactus possesses seemingly limitless, god-like power and can perform a great many feats with it. Below are most of his known abilities.
- Immortality - Galactus is the oldest living being in the universe and does not age.
- Invulnerability - Galactus is immune to all diseases, ailments, and toxins. In addition, he is enormously resistant to damage, but was almost killed by a planetary impact, despite being nourished at the time.
- Energy Manipulation - Galactus feeds on energy and can manipulate and project it as he pleases, often in the form of lethal blasts or barriers.
- Size Alteration - Normally when he has visited Earth, Galactus appears to be the size of a skyscraper. His true size is unknown, though he can manipulate his size at will. He can be the size of a human one moment and the size of a moon the next.
- Transmutation - Galactus is capable of altering the molecular bonds of all forms of matter, remaking and reshaping objects as he chooses.
- Teleportation - Galactus can instantly transport himself or anything else from one point in the universe to another. He has even been known to make entire planets disappear.
- Psychic Powers - Galactus possesses both telekinesis and telepathy.
- Creation - As a cosmic entity, Galactus can create objects or life-forms out of nothing.
- Soul Manipulation - Galactus can even control the souls of other beings whether they be living or dead.
- Resurrection - Galactus can restore dead beings to life.
- Vitakinesis - Galactus is able to heal himself and others from physical wounds although this may simply be molecular reconstruction.
- Power Bestowal - Galactus' heralds, whom he has endowed with a minuscule fraction of his cosmic power, are able to manipulate matter and energy in ways that are far beyond human comprehension.
Galactus' only weakness is his hunger. He is dependent on energy to survive and sustains himself by feeding on entire planets. Life energy is especially nourishing to Galactus and so he has developed a preference for populated worlds, as these assuage his all-consuming need for greater periods of time.