*** SPOILER WARNING: SPOILERS FOR GUARDIANS OF THE GALAXY VOL. 2 BELOW ***

When you take a look at the Marvel Universe's most powerful beings, start first with cosmic entities like Galactus and The Collector... and then look up. That's where the Celestials will be, lording over other galactic giants in stone-cold silent terror. Celestials are gigantic humanoid gods from space who wear imposing armor and are as quiet as the soundless void from whence they come. Their silence doesn't in any way mean they aren't just as powerful as they look--and they do look incredibly powerful. There isn't much known about the Celestials, but we managed to do some digging and came up with some interesting facts about them.

RELATED: 15 Marvel Characters Who Could OBLITERATE The Celestials

Granted, what little we do know about the Celestials scares the ever living crap out of us. Imagine a group of cosmic beings who tower larger than the tallest buildings, never say a word and pass judgment on whether or not your species has a right to continue existing. That's pretty much what a Celestial is in a nutshell and the characters in the Marvel Universe who know of their existence know not to mess with them. If you weren't afraid of them before, get ready to shake in your boots because here are 15 facts about the Celestials that are SCARY AS HELL!

*** SPOILER WARNING: SPOILERS FOR GUARDIANS OF THE GALAXY VOL. 2 BELOW ***

15 SOMETIMES (IN THE MOVIES) THEY ARE PLANETS

Ego the Living Planet in space

If you haven't seen Guardians of the Galaxy Volume 2 yet, you might want to skip this one because of minor spoilers ahead! In the film, Ego, who was brilliantly played by Kurt Russel, was depicted as a Celestial and proves to be arguably the most powerful entity ever seen in the MCU. Interestingly, though, Ego is NOT a Celestial in the comics. It's a drastic change to both Starlord's origin and Ego's as well who is, in the comics, an often malevolent, sentient planet who doesn't muck about the universe in human form getting nasty with as many alien ladies as he can. Most of the time, Ego travels the universe consuming anything in his path to increase his mass.

Ego first appeared in Thor #132, written by Stan Lee and penciled by Jack Kirby. He is a bioverse controlled by his consciousness from the sand to the atmosphere. Though he is very powerful and immense, he is not a Celestial outside of the Marvel Cinematic Universe. Still, it should be mentioned that whatever the Celestials are, in the MCU, they are diverse... and remain terrifyingly powerful!

14 THEY BREED RACES

The Eternals flying through the air

The Celestials have been responsible for creating sub-races, many of which have originated on Earth. When the First Host of Celestials came to Earth approximately one million years ago, they found a species they considered eligible for their experiments: humans. They altered the genetic characteristics of humanity in a number of ways to create two separate races: the Eternals and the Deviants.

The Eternals look very similar to humans, but are nearly immortal and possess godlike powers. Very few Eternals exist due to low birth rates, but they have lived alongside humans since their creation. Deviants are less-powerful than the Eternals, but still, maintain great power over humans. Their altered genes ensure their offspring look nothing like their parents making each generation different than the last. The two groups warred with one another over the years, with the Deviants focusing on their technological prowess over the Eternals' raw power.

13 THEY ARE LEGION AND DIVERSE

Four assembled Celestials in space

There aren't a lot of Celestials, but then, they don't need that many. Because there are just over 20 we know of, each one is a unique individual with their own characteristics and assigned tasks or duties. Their armor is also unique and some carry tools or weapons they use in their duties, which mostly involves destroying planets. It is not known if a Celestial is born into the universe for a specific task or purpose or if they adopted these guises as they developed.

Some of the more prominent Celestials include Arishem the Judge, Ashema the Listener, The Celestial Gardener, Devron the Experimenter, Exitar the Exterminator, Nezarr the Calculator, and the One Above All, who has been called the "leader" of the Celestials. This "One Above All" is the supreme Celestial and should not be confused with the likewise-named character who is responsible for all life in the Marvel Universe (purported to be Stan "The Man" Lee).

12 THEY CREATED SUPERPOWERS

Marvel Superheroes and Villains

Because the Celestials have been screwing around with the human genetic code for over a million years, it should come as no surprise to learn that they are responsible for mankind's ability to acquire superpowers. Their reasons for doing this remain unknown; like most of the details surrounding the Celestials, it is a mystery. What is known is that they are responsible for introducing the X-Gene into humanity as a latent gene around the time they created the Eternals and Deviants. This ensured that the gene was carried down over the years so that mutants could evolve separately from humans.

Other than the X-Gene, their machinations in human DNA has provided the ability to gain superhuman powers. This implies that the Marvel Universe would be devoid of superheroes without the experiments of the Celestials. They have also messed around with the genetic code of other races, such as the Skrulls.

11 EVEN THEIR DECAPITATED HEADS HAVE POWER

Knowhere in Guardians of the Galaxy

Sometime, long ago, a Celestial was murdered. We don't know who it was and we don't know how it happened, but that didn't stop thousands of aliens from setting up a rather nifty base within the head to include the new Guardians of the Galaxy (comic and movie). "Knowhere," as it is called, resides on the edge of the Universe and it serves as the base for the Guardians as well as the Luminals and many other aliens. It is governed by Gorani and the head of security is Cosmo, a telepathic Russian dog who was lost during the Space Race in the 1960s.

Knowhere has been seen on film in the first Guardians of the Galaxy film and made its first appearance in Nova #8, written by Andy Lanning and penciled by Wellington Alves in 2007. Knowhere is a technologically advanced space station with medical facilities, living areas, and a teleportation mainframe called the Continuum Cortex.

10 THEIR ENEMIES ARE INSATIABLE SPACE LOCUSTS

THE HORDE

The Horde is the universe's counterpart of the Celestials. They awoke at the same time as the Dreaming Celestial and are antithetical equivalents in power to the Celestials. They are most often referred to as the locusts of the universe and were drawn to Earth when the Dreaming Celestial was awakened. Both groups are believed to serve the mysterious universal force called The Fulcrum, but not much else is known about them.

The Horde travels the universe consuming the planets whose Deviant population has taken over as the dominant species. This is in direct contrast to the Celestials, who were responsible for the creation of the Deviant race. The Horde first appeared in Eternals #6, written by Neil Gaiman and penciled by John Romita Jr.

9 THEY ARE BORN IN THE DEATH OF GALAXIES

Birth of the Blue Celestial

The birth of a Celestial is a grand and horrible cosmic event, but little is known for certain how they reproduce. Only one Celestial has ever been observed coming into the universe and it was a cataclysmic event, to say the least. Thor witnessed a Celestial's birth within the midst of the Black Galaxy, a bioverse composed of living matter. This happened in Thor #419-425, written by Tom DeFalco and penciled by Ron Frenz.

A huge explosion expanded to the edge of the Black Galaxy but contracted back into the center. This focused all of the matter and energy of the galaxy into a new Celestial, which then came to life. Because this is the only observed Celestial birth, it is not known if they are able to procreate in other ways or if a galaxy is needed each time they are born.

8 THEY SUNK ATLANTIS

Map of Marvel's Great Cataclysm

When the Second Host of Celestials returned to Earth approximately 20,000 years ago, they wanted to check in on their experiments to see how they were developing. They didn't have much of a problem with how the Eternals were progressing, but the Deviants weren't exactly living up to their expectations. The Deviants, in their infinite wisdom, felt it necessary to attack the Celestials as they approached, which is never a good idea for anybody.

The Celestials responded in kind and attacked the Kingdom of Lemuria, the Deviant's stronghold. The resulting explosions sank Lemuria, but they also took Atlantis and other similar civilizations into the depths of the ocean. This event became known as the Great Cataclysm. Around this time, the Dreaming Celestial (we mentioned him before) was sealed within the Diablo Mountains of Earth for a crime he never committed. Every revelation about the Celestials seems to breed more mystery.

7 THEY HATE THE WATCHERS

The Watchers and the Celestials face off

The Watchers are a race of near-infinitely powered cosmic beings who are somewhat similar to the Celestials. The Watchers first appeared in The Fantastic Four #13, written by Stan Lee and penciled by Jack Kirby. They are technologically superior to just about any civilization to ever arise and they have sworn to observe, but not interfere with the development of other species across the universe.

Because of their sworn oath of non-interference, they have come into direct conflict with the Celestials. This is ironic for them since their pact means they can't interfere with the Celestials so their ongoing conflict is conducted via third parties. The two races of nearly all-powerful space gods recently battled using gigantic versions of themselves, but their conflict was not conclusive.

6 EARTH HAD A BABY CELESTIAL INSIDE IT

Celestials in Marvel Comics' Earth-X walking through a city

In the alternate reality of Earth-9997, otherwise known as Earth X, the Celestials are on a constant quest to avoid stagnation, having discovered everything in the universe and achieving technological superiority at an early time. After discovering the universe's secrets, they turned their attention inwards to study their own biologies and transformed themselves into immortal beings of immense power whose energy required a suit of armor to maintain cohesion.

In this reality, the Watchers are a subservient race who watch over the Celestial embryos, which are laid within planets. Earth has a Celestial embryo within it and when the Fifth Host arrives to destroy the planet and give birth to their new member, Franklin Richards (who has become Galactus) is able to stop them by removing the embryo and consuming it, thus revealing his TRUE purpose as the Devourer of Worlds.

5 THEY WAR WITH GODS

The Fourth Celestial Host assembled against Odin in the Destroyer Armor

When you are a race of immeasurably powerful space gods, it stands to reason that you might take up arms against a similar group of all-powerful beings. That's what happened when the Fourth Host arrived on Earth in the 20th Century, to check the progress of their experiments. Fearing that the Celestials would destroy Earth, the Eternals and Asgardians joined forces against them. The Eternals were killed for betraying their creators, but Odin was able to augment his Odin Force with the unstoppable Destroyer Armor and every Asgardian soul in existence, just to battle the Celestials. And yet, even with all of that divine power, it did not work out for Asgard.

Before the Celestial known as Arisheim the Judge could pass judgment on the Earth and end Thor's life, Gaea offered up the Young Gods to prove humanity's worth. Arisheim seemed pleased and decided the Earth could continue existing for a little while; hence, the Fourth Host departed the Earth, leaving the Asgardians in ruin.

4 THEIR ORIGIN REMAINS A MYSTERY

A group of Celestials from Marvel Comics

One of the more fascinating aspects of the Celestials is that their origin remains a mystery. There have been several theories as to their beginnings thrown about in the comics over the years, but nothing has ever been confirmed. Some of the many theories regarding their origins include them being a race of beings left over from a previous universe or that they were created and serve Fulcrum to maintain cosmic balance alongside the Horde.

Whatever their origin may be, they are a race of engineers and scientists who have made it their mission to experiment on the various races of the cosmos for their own purposes. It is unlikely Marvel will shed much light on their origin as the mystery of the Celestials is what makes them such interesting and truly terrifying cosmic beings. If we all learned they were the dreams of Franklin Richards, it would take some of the threat of their being away.

3 NOT MUCH CAN HURT (LET ALONE KILL) THEM

Nezzar regenerates his arm in a battle with Thor

We already know that Celestials are godlike beings who tower over the other races of the universe with immense power, but they can be hurt or even killed... one of their decapitated heads if a space station after all so we know this, but how exactly do you harm an armored space god? It turns out that it's not as easy as you might think. Throughout the course of their 40 years of publication history, there have only been a few instances depicting their injury... well, damage to their armor in any event.

Thor successfully removed the Celestial Nezzar's arm with the Odinsword, but it immediately regenerated. When Thanos wielded the Infinity Gauntlet, he used its ultimate power to destroy them and the all-powerful Beyonders can kill them if they want. Franklin Richards' powers rival their own and they have come into conflict on numerous occasions across the various Earth realities.

2 THEIR TRUE POWER IS YET UNKNOWN

In a lot of ways, this goes without saying, but we wanted to delve into just exactly what these armored space gods can actually do when they act. We have already mentioned their ability to create life and alter the genetic code of whichever species they desire to create new offshoots or superpowered versions of them, as well as their ability to regenerate lost limbs and easily defeat the Asgardians, but there is a lot more they can do.

When the Fourth Host left Earth, they removed the knowledge of their existence from the entirety of the planet. Only a handful of people have any memories of their very existence, not to mention, their past activities on the planet. They can open and close dimensional portals and are at the height of technology such that humans can't even fathom their abilities.

1 THEY HAVE A MEGAZORD

Exitar the Exterminator

When the average Celestial stands at around 2,000 feet in height, you wouldn't think they needed a larger version for... well, anything, but then how would we explain Exitar the Exterminator? Exitar first appeared in Thor #387 in 1988. His only task is to destroy the planets housing the races the Celestials have determined to have failed their tests. If the Fourth Host wasn't swayed by the Young Gods, it would have been Exitar who would destroy the planet. And he would have done so easily.

Exitar was summoned to destroy the Earth by Arishem, but fortunately, his hand was stayed, which is a good thing because he could sit on the planet and kill most everyone on it. His size makes him tower over his peers and it has no known limit. Exitar can travel through time and space as he sees fit and truly stands as a space god.

Did we miss any facts about the Celestials that make them terrifying AF? Sound off in the comments and let us know!