We know them. We love them. We're talking about monsters.

In the 1950s, monsters ruled the comic book industry. That was partly due to the end of World War II, which took away the Nazis that had driven so many superhero comics in the '40s, and caused the genre's popularity to decline. Comics about romance and horror became more popular, driving EC and Atlas Comics (which eventually became Marvel Comics). Before the Fantastic Four revived superhero comics in 1961, exotic monster stories were what sold copies. One of the masters of the genre was Jack Kirby.

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Kirby was one of the most prolific writers and artists in the industry, and he wrote countless stories about horrific creatures, which pushed the boundaries of the Comics Code. In September, Marvel announced it would pay homage to this "monstrous" lineage by releasing a crossover event called "Monsters Unleashed," which would bring its stable of superheroes up against many of its classic monsters. In honor of the event, CBR runs down 15 of Kirby's craziest creations.

15 Gor-Kill the Living Demon

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Kirby had a great flair for names like "Kamandi, the Last Boy on Earth." But usually, the better the name, the worse the monster.

"Tales of Suspense" #12 in 1960 was set in a small coastal town in a European village, where a sentient floating gas cloud arrived from space. Yeah, the monster in this story is a cloud.. sort of. You see, the cloud could only turn solid if it came in contact with water. Fortunately, we have plenty of water on Earth. The cloud alien took over the water held back by a dam, and began terrorizing the town. The townspeople named it after a local legend, Gor-Kill the Living Demon.

Gor-Kill threatened to get into the ocean, where it would become even more powerful. The only thing stopping it was an explosion with dynamite, which dispersed it and caused the water to sink into the ground. But remember, Gor-Kill is just a lot of water. But hey, "Living Demon" sounds a lot better than Gor-Kill, "the Living Gallons of Water."

14 The Monster at the Window

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"Tales to Astonish" #34 in 1962 included a story called "The Monster At My Window." It told the tale of Paul Marshall, a science fiction writer who woke up one night to see a hideous monster outside the window of his apartment. He did what we all do, which is scream, before it disappeared. He thought it was just his imagination, but throughout the day kept feeling watched. That night, he saw the monster at his window again, but when he looked outside, it was gone.

The monster would return later, standing outside his house. It chased Marshall through his apartment building, smashing through walls and doors. No one could hear him scream. The monster finally cornered Marshall on his roof.

This is all pretty creepy stuff, which should make this monster one of Kirby's best. But the ending is where it fell apart. It turned out the monster didn't want to eat or kill Marshall. It actually just wanted Marshall to write nice stories about it so Earthlings would think it was friendly, softening us up for an alien invasion. It wanted to pull a stunt like the alien race in "V" and convince humans we were its friends before secretly invading Earth.

A monster who forces you to write science fiction. Wonder if Kirby was thinking of his editors?

13 X, The Thing That Lived

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It seems like Kirby got a little frustrated with this one, because he basically wrote a story about himself.

In "Tales to Astonish" #20 (1961), a comic book writer named Charles Bentley is struggling to come up with original monsters. Sound familiar? But in this story, Bentley seemed to have a better time of it than Kirby. Bentley got an idea to write a story about a sea monster. Sort of like Godzilla, but a serpent instead of a dinosaur. After the book was published to huge success, the government came to ask how he knew about the sea serpent they had just attacked. Turns out it was real! When they were convinced he was telling the truth, Bentley wrote another story about a two-headed monster, but was shocked when the exact same creature attacked.

Not learning his lesson, Bentley wrote a story about the ultimate monster, one from another dimension which could change its shape and size at will. His editor loved it so much he gave Bentley a bonus and a week off. Again, this was Kirby's fantasy.

But hold onto your butts for this shocker, because the monster he created? It came to life. Yes, it's "X, the Thing That Lived," which is much worse than "W, the Thing That Immediately Died."

Fortunately, Bentley destroyed it by throwing his typewriter out a window. It turns out his typewriter was behind it all along.

12 Orrgo the Unconquerable

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One thing Kirby loved was to create monsters with incredible and unstoppable powers, and Orrgo from "Strange Tales" #90 (1961) is a great example.

The story started with a group of aliens watching Earth, promising to conquer it, like an entire race of Doctor Dooms. Orrgo boasted that his race was so powerful, they only needed one of their people to do it. He beamed himself across the universe to Earth with the power of his mind alone. For some reason, he decided to transport himself to a circus to announce his arrival instead of the United Nations. That proved to be his undoing.

Orrgo proceeded to prove his power to Earth by making mincemeat out of the military. He turned the jet planes into birds, and brought trees to life to attack the soldiers, like an army of Groots. He even ripped an entire city out of the ground, making it levitate into orbit, and turn upside-down. He capped it all off by hypnotizing the entire world to do his bidding, which, really, he probably should have started with. When he was done, Orrgo lay down to take a nap.

At that point, a gorilla escaped from its cage and bashed Orrgo's head in. Bet you didn't see that coming! Yes, Orrgo wasn't unconquerable. His real weakness was a gorilla's fist.

11 Infant Terrible

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In "Fantastic Four" #24 (1964), Kirby created one of his most dangerous and weirdest monsters: the Infant Terrible.

While the Fantastic Four were in the middle of a photo shoot, they got reports of something strange attacking New York City. They went outside to find a bizarre scene.

First, they got trapped inside a giant milk bottle. Then, a bunch of mechanical soldiers marched through the city. Then they saw a weird-looking alien turning a lamppost into berries, and making soda pour out of a wall. Reed Richards correctly figured out that the alien creature was a child with the power to change reality, much like the children in episodes of "Star Trek" and "Twilight Zone." When the alien accidentally caused a meteor shower to crash into the city, Reed worried that the giant baby would destroy the world by bringing the sun closer.

When they tried to contain it, Infant Terrible went on a rampage, making a giant rock monster, and solidifying clouds to make them crash to the ground. Fortunately, Reed sent out a distress signal, which called Terrible's parents to come get him.

Kirby proved that the most dangerous thing in the universe is a child. Something tells us he had a problem with kids.

10 Trull the Inhuman

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Trull the Inhuman had one of the greatest names and greatest covers and greatest concepts in all of Kirby's stable... but with the worst execution.

In 1961's "Tales to Astonish" #21, an alien spaceship crash-landed in the jungles of Africa. The captions told us the occupant named Trull was dying, but he was a native of the "Delta Centurius Galaxy," where people can separate their "life essence" from their physical bodies at will. That's right, the entire Galaxy has this power. Pretty handy. The only catch is that the body has to be mechanical. With his advanced mind and immortal spirit, Trull planned to find a new body and conquer Earth.

Cut to Phil, an engineer who was working on a state-of-the-art steam shovel near the crash site. Trull invaded and took control of the steam shovel, enslaving Phil and the construction workers, and announcing his plans to rule with his new body. But Phil got an elephant to charge the vehicle, cracking the shovel's cylinder and forcing Trull to leave it. With no other machines around to seize control of, Trull evaporated away.

So when you boil it all down, Trull the Inhuman is a killer steam shovel. We hope that story didn't leave too many kids waking up in the middle of the night, terrified of construction equipment under their beds. In all actuality, Trull was so popular with readers that he eventually returned in "Civil War II," facing Damage Control. You can't keep a good shovel down.

9 Spragg

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In "Journey Into Mystery" #68 (1961), Kirby introduced Spragg, a member of a race of aliens that mixed with Earth's molten core to form lava monsters. The aliens lived underground for centuries while humans lived unaware of their existence. Unfortunately, one of the Spragg was cast out of their society and forced to travel to Earth's surface in Transylvania. While there, it enslaved the locals with hypnosis and forced them into building a machine to boost its powers.

That all sounds pretty good, until you realize that Spragg is really just an evil hill. That's right, a hill. Not even a mountain. He's just a big pile of rock who doesn't even have arms and legs. He can't walk or chase you or even touch you. All he can do is roar with a big mouth. If it wasn't for his hypnosis powers, people would just laugh at him and walk away. Or turn him into a landfill.

At the end of the episode, a scientist manages to hook Spragg up to a rocket and blast him into space. Because it's not like Spragg could run away or anything. Spragg actually returned in later issues, and even had a cameo in a She-Hulk comic! Although popularity for him remains an up-hill battle.

8 Poker Face

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Definitely one of the strangest monsters Kirby created was Poker Face in the aptly titled, "Strange Tales of the Unusual" #7 (1956).

In the story, a cylindrical spaceship arrived on Earth, out of which a huge skinny alien walked, right into a city in Russia. It looked sort of like a carrot mated with broccoli. With the Cold War in full effect, the Soviet Union attacked.  Did the alien fight them back? Did it shoot out strange laser beams or hypnotize or crush them with its giant head? No, it didn't even seem to notice. The alien began traveling all over the planet, studying and operating strange machinery. The armies of the world attacked it, but bullets and missiles just bounced right off while it continued to examine different areas of the planet. It had a Poker Face. Get it?

In the end, it turned out Poker Face wasn't here to destroy or conquer Earth. It told an old prospector that it won Earth in an intergalactic poker game, but it left because our planet didn't have a rare mineral it was looking for. Poker Face is the most boring monster Kirby ever created, because it doesn't actually do anything at all. Well, besides "not die."

7 Zzutak

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This was another Kirby monster with a great name. It was also known as "The Thing That Shouldn't Exist."

"Strange Tales" #88 (1961) stars Frank Johnson, an artist who's trying to come up with a new monster. While at work, a mysterious man knocks on the door and offers him "three-dimensional paint." The paint makes anything he paints become solid. He's excited about it, but finds himself mysteriously drawn to Mexico to paint. There, he finds an ancient Aztec temple where he was compelled to paint a monster. Of course, the monster come to life, even though it shouldn't exist!

It turns out that the mystery man was a "medicine man" from an ancient Aztec tribe who created the three-dimensional paint. They gave it to Johnson so he could paint monsters, which they could control to rule the world. But Johnson painted a second monster and ordered it to attack the first, defeating Zzutak and the evil plan. That Kirby sure did like getting autobiographical.

6 The Thing Called It

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"The Thing Called It" was sort of like if Frankenstein had used plastic instead of dead bodies. In "Strange Tales" #82 (1961), a frustrated scientist named Heinrich Munch decided to kill his rival with a monster. He used plastic to create a huge creature, poured in a titanium and sodium mixture, and used electricity to bring it to life. Why sodium and titanium? Honestly, Kirby was just naming random stuff to throw in. Because, of course, everyone knows that plastic, titanium and sodium are key to artificial life.

Unsurprisingly, the plastic husk didn't come to life. In disappointment, Munch dumped the creature into the quicksand outside his castle. Somehow, the quicksand contained the chemicals that brought It to life. The monster returned to Munch, who ordered it to kill his rivals. But it turned out the creature grew a conscience, because it refused. In rage, Munch tried to blow it up, but a stray lightning bolt transferred the monster's consciousness into Munch's body.

Like they said in "The Graduate," the future of monsters is all about plastic

5 The Thing That Crawled By Night

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There are a few words that make you think of fear and terror. "Thing" is one. "Crawl" is another. "Night" is another good one. That's probably why Kirby named this one "the thing that crawled by night." And once again, he used a great name to cover for a not-so-great monster.

"Tales of Suspense" #26 (1959) introduced readers to Jed Hanson, a humble farmer working to feed the world. He was trying to create a plant that grows in all conditions without water when a meteor crashed near his farm. He didn't think much of it, until his plant started to grow. But it kept on growing, crushing everything and running through his farm and into town. The vines of the plant grabbed and crushed everything around it, including animals, tractors and buildings. Fortunately, Hanson discovered the meteorite was harmful to it, and used pieces of it to shrivel and stop the plant.

That'll teach Hanson to try to help other people.

4 Mangog

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Most of Kirby's monsters tended to be lumpy and scaly more than scary-looking, but he really went all out with the look of Mangog. He gave it claws, a tail and a huge gaping face with horns and fangs. He also gave it a great name.

Mangog first appeared in "Thor" #154 in 1968, but continued in a storyline running until #157. When Thor's enemy, the troll Ulik, was looking for a way to fight the gods, he found a cave with the remnants of an ancient alien race that once almost destroyed Asgard. Breaking open the cave freed Mangog, a being made of the combined hatred of a "billion billion" members of the Vanir, a race killed by Odin himself. Mangog was so mad, he wanted to end the universe with Ragnarok.

Mangog made his way across Asgard, punching out frost giants, crashing through the castle of Odin and running through all of Asgard's greatest warriors, all in a bid to draw Odin's sword, which would bring about Ragnarok. Thor fought Mangog, but could only stop him by bringing the Vanir back to life, which shrank Mangog down to a manageable size. But Mangog continued to return again and again to try to bring Ragnarok, because (as he explained to Thor) hate can never be destroyed.

3 Goom

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This monster had a great name and a great look. In "Tales of Suspense" #15 (1961), an astronomer named Mark Langley had a theory that got him laughed out of the scientific community. He believed that other planets existed in the solar system, but we couldn't see them because of warps in space and time. He really should have been laughed at for that, because it makes no sense. But Langley persisted and found a planetoid near Jupiter he called Planet X. He sent a signal to the planet to search for life.

Fortunately, he was successful. Unfortunately, he was successful in contacting Goom, "the Thing from Planet X."

Goom was quite a character. He could fly, thanks to lower gravity, and had incredible strength. Like many of Kirby's alien monsters, Goom was also a scientific genius, thanks to his enormous head. He had a gun that could disintegrate entire mountains and even a "time machine." Unlike Doctor Who's TARIS, Goom's was really a box that could reverse the aging of anyone he put into it. Goom also stole a trick from Orrgo by ripping a city out of the ground and levitating it with his mind.

But Goom's weakness turned out to be his own people. Langley sent a distress call to Planet X, and more of Goom's race came to take him away. Langley explained that such an intelligent species couldn't all be bad. Goom eventually returned, and became a staple character in the Marvel Universe, where he fought the Fantastic Four and the Hulk, because he was awesome.

2 It, the Living Colossus

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In "Tales of Suspense" #14 (1961), an alien ship crashed into a remote area of the Soviet Union, where a sculptor had been working on a colossal statue to honor the government. The ship's lone occupant was a crab-like alien called a Kigor, who had the technology to climb into the statue and bring it to life. The statue became "IT, the Living Colossus," rampaging across the land and even into the ocean, wreaking destruction. It was only stopped when the alien rescue ship arrived, and the crab-like monster inside left the stone monster behind.

But the story didn't end there. IT was so popular that the "living colossus" returned in "Tales of Suspense" #20, where the same statue was sent to Los Angeles on loan. Another Kigor possessed the statue and rampaged through the city until a special effects technician named Robert O'Bryan created what appeared to be a better statue, which the Kigor decided to take instead. But the new statue turned out to be full of explosives, destroying it.

That left the original IT behind for O'Bryan, who gained the ability to control the giant statue in "Astonishing Tales" #21 (1973). The cover claimed IT was more powerful than King Kong, which is probably true. The series was short-lived, but established the Living Colossus as a major force in comics.

1 Fin Fang Foom

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Without question, one of Kirby's most famous monster creations is Fin Fang Foom. The outrageous Chinese dragon has come to symbolize his crazy flair for making new monsters and remains relevant today.

First appearing in "Strange Tales" #89 (1961), the story of Fin Fang Foom started with a Chinese teenager named Chan Liuchow. Chan lived on an island about to be invaded by Communist Chinese forces, and went to a sacred tomb under the Great Wall of China. There, he used a rare herb to awaken a sleeping creature resembling a dragon: Fin Fang Foom. Chan was able to get the dragon to chase him to the ocean, where Foom demolished the Chinese military. Chan put Foom back to sleep, but the monster was so popular that it returned again and again.

Later issues established the monster's backstory as a member of an alien race of shapeshifters, and Foom was one left behind. The supervillain the Mandarin once gained control of Fin Fang Foom, and used the dragon as a weapon against Iron Man. As an Iron Man villain, Fin Fang Foom became one of his most popular enemies. Meanwhile, Foom established Kirby as a creator of some of the wildest monsters ever invented.

Excited for "Monsters Unleashed?" Who are your favorite Marvel Monsters? Let us know in the comments!