Unicron vs. Galactus: Which Colossal Planet Devourer Would Win in a Fight?

The world of fiction is home to a lot of powerful entities that are strong enough to threaten entire planets alike. Some of these entities, of course, are so powerful that they have the capability to devour planets. Two of these entities include Transformers’ Unicron and Marvel Comics’ Galactus, who are both so powerful that they could threaten the entire universe. So, in a fight between Unicron and Galactus, who would win?

It is likely that Unicron will win in a fight against Galactus. That’s because Unicron himself is a multiversal threat that has already consumed entire universes in the past. On the other hand, Galactus is at the level of a universal threat as he doesn’t exist as one entity throughout the entire multiverse.

The thing about the world of fiction is that it can be quite difficult to compare the powers of different characters because they all scale differently compared to one another. But we can all agree that a being that could threaten the entire multiverse is more powerful than someone who is a threat to the universe, regardless of the fictional world we are looking at. In that regard, let’s look at this battle in greater detail.


Unicron is known to be a very large entity that exists as one single entity regardless of which universe we are looking at. His size tends to vary depending on the continuity we are looking at, but the fact of the matter is that Unicron is so large that he is as large as an entire planet. In some instances, he is half the size of Earth, but there are some instances where he is just about as big as Cybertron, which is a planet that’s the size of Saturn (120,000 km in diameter). As such, he is an incredibly huge entity that could trump the size of Earth itself.

Galactus has always been known as the large space creature that tends to eat planets to sustain himself, as there is no doubt that he is an extremely large entity that could also threaten the entire universe. In most cases, Galactus is right around 29 feet tall, depending on how full or hungry he is. However, there are some instances when he is larger than an entire planet. But that is merely how people perceive him, as that isn’t the actual size of his true form.

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While Big G is indeed very big and is just about the size of a building, the thing is that Unicron is as large as an entire planet and is sometimes even bigger than the Earth. As such, Unicron easily takes this round.

Unicron 1, Galactus 0


In the fictional world of Transformers, Unicron is said to be so powerful that he could consume entire planets at will instead of simply consuming one planet after another. He is a large transformer that’s the size of an entire planet and can even transform into a planet whenever he consumes other planets. On top of that, Unicron has the ability to travel across multiple realities because he is a being that exists across all of the different universes in the Transformers continuity.

Galactus is a cosmic entity that is the only survivor of the last universe before the current Marvel universe. He sustains himself by eating entire planets, as that is what allows him to make use of an incredibly powerful source of power called the Power Cosmic, which allows him to obtain powers that are so incredible that Thanos, with the Infinity Glove, ranked him as a being that is just as strong or even more powerful than other beings like the Celestials and the Skyfathers. And with the Power Cosmic, he is shown to be godlike in terms of his overall powers.

The thing about Unicron is that his powers aren’t as fleshed out when compared to someone like Galactus, who has been around for a very long time and has always been one of the most powerful figures in Marvel. As such, we are giving this round to Big G.

Unicron 1, Galactus 1

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Threat Level

While Unicron doesn’t have a lot of storylines that explain his powers really well, the thing is that he is and has always been a threat to the entire multiverse instead of being a threat to one single universe. That means that entire universes have been threatened by Unicron’s powers as he has the ability to not only eat entire planets but also stars and galaxies as well. This makes him arguably the biggest threat to ever exist in the entire continuity of Transformers.

As mentioned, Galactus is a cosmic entity that existed in the universe before the current Marvel Comics universe, as he was the only one to survive the destruction of his own universe. He lives to eat entire planets because that is what sustains him and keeps him alive. But the thing about Galactus is that he is a universal threat as different planets all over the universe are afraid of what he could do if he gets hungry. 

There is no doubt that Unicron is an even bigger threat to Galactus because his world-eating powers allow him to consume entire universes. On the other hand, Galactus is known to have different versions in each universe as he is a universal threat and not a multiversal one.

Unicron 2, Galactus 1


A lot of the powerful opponents that the Autobots had to face during the entire Transformers continuity were actually heralds of Unicron. The purpose of these heralds is to conquer an entire planet and weaken it to the point that it would be easier for Unicron to consume these worlds. Of course, the strongest heralds of Unicron include the likes of Galvatron, Scourge, and the Fallen, who are all at the level of someone like Optimus Prime or Megatron.

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Galactus is known to be a world eater that sends out his heralds to different galaxies all over the universe because he wants to send out these advanced scouts to seek out worlds that have enough life sources for him to eat. As such, these heralds are given a portion of the Power Cosmic, which allows them to have near-godlike powers that are almost at the level of Galactus’s own control over the Power Cosmic. Some of these heralds include the likes of the Silver Surfer, the Fallen One, Morg, and Nova.

We’ve seen what the Silver Surfer can do as a herald of Galactus, and he is already godlike in terms of his overall powers and abilities. That means that the heralds of Galactus are stronger than the heralds of Unicron.

Unicron 2, Galactus 2


Because Unicron is a character whose storyline isn’t as fleshed out as some of the storylines of the other villains that exist in different fictional worlds, we aren’t that familiar with his feats. But what we do know is that he is powerful enough to be able to match or destroy the likes of Primus and Cybertron, who are also planet-sized entities that have incredible powers. Of course, we also know that Unicron has destroyed entire universes in the past as well.

Being able to survive the destruction of his own universe is one thing but threatening the entire Marvel universe is an entirely different thing as well, as Galactus is so powerful that he has defeated entire superhero groups in Marvel. On top of that, he is much stronger than a Celestial, as he once took oh multiple Celestials before getting defeated when they combined to defeat him. In that regard, matching the power of multiple Celestials is a testament to just how strong Big G is.

While Galactus may have feats that are very impressive, the thing is that he is yet to destroy an entire universe, as Unicron has actually devoured multiple ones in the past. That’s why Unicron takes this round.

Unicron 3, Galactus 2

Unicron vs. Galactus: Who Wins?

We all know that there are plenty of Marvel Comics fans that believe that Galactus would win in a fight against Unicron. He does indeed have a chance to defeat this planet-sized transformer because of his Power Cosmic. But the thing about Unicron is that he is capable of destroying entire universes and is a threat to the entire multiverse instead of just one single universe. As such, it is hard to choose a universe-level threat over someone who is known to have destroyed multiple universes in the past.

  • Ysmael is a self-professed geek that loves anything related to fantasy, sci-fi, video gaming, and anime. Spends his free time watching movies, TV shows and gaming, a lot.