When it comes to Big Bads in the Marvel Universe, they don’t come bigger than Galactus. In terms of sheer size and raw power, the World Devourer dwarfs most of the heroes and villains in the Marvel Universe. Able to manipulate cosmic forces effortlessly, Galactus’ only weaknesses are his own hunger and the power of an Infinity Gauntlet-wielding adversary.
Although his omnipotence is well established in the Marvel Universe, how would he fare in the DC Universe, with its own set of universe-bending baddies?
10 DEFEAT: SINESTRO
Sinestro is by all accounts an extremely powerful adversary, capable of manipulating the yellow power of fear with a skill afforded few ring-slingers in the DC Universe. Aside from that, he’s the head of his own Corps.
Despite his prowess, he would stand little chance against the might of Galactus. Sinestro’s power comes from harnessing one specific cosmic energy, and it’s quite feasible that Galactus would be able to either figure out how to negate or control it himself or use other powers at his disposal to pacify Sinestro decisively.
9 LOSE: DARKSEID
Darkseid is one of the most powerful beings in the DC Universe, a literal God whose formidable physical abilities are capped off by the Omega Effect, a powerful energy burst that can destroy, transmute or transport an adversary in seconds. Truth be told, even with all his abilities, Darkseid would be at a disadvantage against Galactus.
However, as their meeting in the Darkseid vs Galactus: The Hunger one-shot illustrated, Darkseid's ruthlessness and cunning is something even Galactus would be unprepared for, ensuring Darkseid at least a stalemate, if not a victory, in a potential confrontation.
8 DEFEAT: DOOMSDAY
Doomsday is an unstoppable force in the DC Universe. Not only possessed of a multitude of offensive capabilities powerful enough to kill a Superman, but the monster is also genetically designed to resurrect from the dead impervious to whatever killed him.
Normally, this would give pause to any being with some good sense, but for a cosmic being like Galactus, Doomsday would be an anomaly he could dispose of relatively easily. After all, possession of the power cosmic and the ability to reorder matter and energy at the subatomic level could see Galactus eliminate Doomsday from existence, or worse yet, make him a new herald!
7 LOSE: THE ANTI-MONITOR
There's no denying that Galactus is a formidable cosmic threat, able to dictate the destinies of countless worlds in countless galaxies in the Marvel Universe. But even his abilities pale in comparison to that of the Anti-Monitor, whose power is able to affect multiple universes across the multiverse.
Although it is feasible that Galactus may able to figure out some sort of offense against him, it would mean little to a being who has the power to end all life in a universe before he moves on to the next one. Quite simply, Galactus would be outclassed in a battle.
6 DEFEAT: LEX LUTHOR
It might seem ridiculous to place a mere mortal like Lex Luthor on a list of cosmic contenders, but considering this "mere mortal" has had the ability to garner a power ring, splice his DNA with a Martian's, merge with Brainiac and run shoulder to shoulder with Perpetua, its seems like he's earned his spot.
Luthor's definitely got the brains and drive to get the better of Galactus, but he'd better make sure he gets it right on the first shot. If he doesn't, he'll be at the mercy of the World Devourer, which will end in a sound defeat.
5 LOSE: KRONA
A Maltusian with a high degree of scientific curiosity, Krona was interested in cosmology before an accident shattered the universe into a multiverse and led the Maltusians to become the Guardians of Oa. Their first act was to imprison their former colleague, but Krona was able to escape.
Over the years, he has managed to gain immense powers through mastery of the emotional spectrum, as well as joining forces with Nekron, to name a few. As such, Krona would be able to handle the threat Galactus could potentially pose quite deftly, provided he maintains his focus, as he did in the JLA/Avengers crossover.
4 DEFEAT: BRAINIAC
In most continuities, Brainiac is a space-faring computerized collector of knowledge and culture. Collecting and shrinking cities from worlds across the universe to add to his collection, Brainiac adds their scientific and offensive capabilities to his own, making his vessel and his person formidable enough to give the Man of Steel a run for his money.
Despite his considerable power, Brainiac would be at the mercy of the raw might of Galactus. The only hope Brainiac could have of besting the goliath would be to infiltrate Galactus' shipboard computer systems but even that would be a longshot for a being as technologically advanced, infinitely wise and savvily experienced as the World Devourer.
3 LOSE: MISTER MXYZPTLK
Few DC antagonists are as mischievously mercurial as the miniature Mister Mxyzptlk. An imp from the 5th dimension, Mister Mxyzptlk usually appears to taunt Superman, until he can be tricked to say his name backward, which sends him back to his own dimension.
An omnipotent being of immense and seemingly limitless power, Mister Mxyzptlk functions like Q from Star Trek, in that anything he wishes to happen becomes reality. The upward scale of his capabilities has never been solidly tested, and as most powers in this universe are subject to his whims, so would Galactus. That is, of course, unless he can trick Mister Mxyzptlk to say his name backward...
2 DEFEAT: STARRO
Starro may look like a ridiculous excuse for a galactic conqueror, but make no mistake, this extraterrestrial starfish is a galactic menace. Able to conquer entire worlds by releasing similarly-shaped clones of itself, the clones attach themselves to the inhabitants of the planet and subject them to Starro's mental control.
The 'mother' entity also has a wide range of abilities that make it formidable, including energy projection and absorption and a degree of invulnerability. Not that it would make much difference against Galactus. Starro's only recourse would be an attempt to control the World Devourer through telepathy, but Galactus' formidable mind and psychic ability would overpower Starro in no time.
1 LOSE: LUCIFER
Lucifer is one of the most powerful beings in the DC Universe, second only to The Presence. Subject only to the omnipotent power of that entity, Lucifer can literally do anything he wishes, from space and time manipulation to the bending of the laws of physics.
Against this type of celestial power, Galactus would prove impotent, subject to the nefarious whims of the first of the Fallen. Should he even attempt to go toe-to-toe with this cosmic entity, Galactus would surely only prove to embarrass himself.