Pacific Rim: 15 Things You Never Knew About Kaiju


From the moment "Pacific Rim" was announced, the idea always boiled down to one thing: giant robots fighting giant monsters. The robots got a lot of attention, but there was no denying the appeal of the huge creatures known as"kaiju." They were more than just big beasts for the robots to pound on, because there was a lot going on with the monsters behind-the-scenes, and the film crew spent a lot of time and effort to make them.

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Some things about the kaiju you might not have noticed if you only saw the movie once. Even if you've seen the movie 100 times, there are still some interesting facts behind the scenes you wouldn't get. With development ongoing in the sequel, "Pacific Rim: Uprising," CBR is here to count down 15 things you didn't know about the kaiju.

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If we're gonna talk about kaiju, then we should start with the word itself. Even though "Pacific Rim" made it more popular in the West, the movie didn't invent the word, because "kaiju" is actually a Japanese word that's roughly translated as "strange beast." Americans just think of kaiju as "giant monsters," but it really means the giant monster genre of Japanese TV shows and movies.

The first and most famous kaiju that most movie fans think of is the titular creature from the 1954 movie "Godzilla," about a giant fire-breathing dinosaur-like creature brought back to life by nuclear testing. There are lots of other Japanese monsters like Mothra that can be considered kaiju, and there's even a giant Frankenstein's monster in 1965's "Frankenstein Conquers the World." The Japanese made the kaiju an analogy of the rampant destruction of the nuclear bomb, but in "Pacific Rim," kaiju were inter-dimensional monsters that come out of a breach at the bottom of the ocean.



The kaiju of "Pacific Rim" are awesome, but still feel familiar, because they're inspired by the Japanese monster movies of the '50s and '60s, which have a special place in the heart of the director Guillermo del Toro. Many of the movie's fans share the same love of watching giant monsters smash their way through cardboard cities, and "Pacific Rim" pays homage to those old films, including the designs.

Most of the kaiju from the old movies had to be made with stuntmen wearing rubber outfits. Unlike those old movies, the giant monsters in "Pacific Rim" are all computer-generated, so they could look like anything, but del Toro went in the opposite direction. He told his designers to make all the kaiju look like something a human being could fit into. In other words, they look like men in suits. However, del Toro ordered the team not to rip off their designs from existing kaiju, but rather come up with new ideas.



The kaiju in "Pacific Rim" are a collection of weird and stylish creatures that make the movie fun to watch. One reason why the kaiju are so great is that only the best of the best made an appearance. That was what del Toro wanted, because he didn't just hire a bunch of designers, have them hand in kaiju designs, and take what he got to put them on screen. Nope, del Toro did what he called an "American Idol"-type competition to vote on designs, and get the best of the best.

Del Toro had the production team design 40 different kaiju silhouettes and then had everyone vote on which ones they liked best. Then they eliminated the lowest-ranking kaiju and voted on the winners. They kept doing that until only nine were left, the cream of the crop, and those became the kaiju which would appear in the movie. They basically held a tournament and the winners made the team.



Just like the kaiju in "Pacific Rim" could have been any shape but stayed in the form of men in suits, they also could have been unearthly creatures that have never been seen on Earth before. After all, it's CGI. There could have been giant worms or glowing balls of light. Del Toro gave the designers another order, which was to make the kaiju based on real animals, and they knocked it out of the park.

The kaiju all have animal qualities that make them seem familiar. For instance, the brawling creature Leatherback walks on huge oversized arms like a gorilla. The creature Onibaba that terrorized the young Mako Mori in a flashback has multiple legs and claws like a crab. That's a callback to the original Japanese kaiju, who usually had qualities of different animals like the giant moth Mothra and the giant praying mantis Kamacuras in 1967's "Son of Godzilla."



The movie described the kaiju blood (called "kaiju blue") as being toxic. There's more to that side of them, because the creatures are toxic in every way. Everything about the kaiju is poisonous, including their blood and excrement. Whenever a kaiju is hurt, its blood spreads everywhere, covering the city in noxious glowing ooze. When the kaiju dies, its body decomposes, and the kaiju blue turns into a poisonous mist that spreads through the air. If anyone breathes in the mist, they go into shock and can die.

The toxic nature of the kaiju isn't an accident. The aliens that created them, called the Precursors, wanted the kaiju to be as damaging to humans as possible. The kaiju are basically biological weapons made to destroy as much of the Earth as they can. Just walking on the ground, a kaiju is causing disaster. When they die, the monsters ruin the ground around them, making any attempt to stop them a pyrrhic victory.



Watching "Pacific Rim," it would easy to call the kaiju "big, dumb monsters," but that would be a huge mistake. The kaiju are definitely big and they are monsters, but they aren't dumb. In fact, the kaiju are smart enough to make anyone who fights them regret thinking they could just shoot at them until they die. In fights with the kaiju, Earth and the jaegers have seen the giant monsters pull off some major moves.

For one thing, the kaiju can communicate with each other telepathically, which allows them to coordinate their attacks. It works sort of like the drift in the jaegers, where they can work together, and we saw in the Triple Event that the kaiju weren't just standing around. They were pulling off sneak attacks and targeting critical parts of the jaegers. The kaiju also have two brains; one to handle cognitive and motor functions in the front and a second brain in the back of the body. That also gives them a boost of intelligence.



Given their destructive power and toxic nature, a kaiju attack is more like a natural disaster than an animal attack. That's probably why the kaiju are sorted into categories, just like hurricanes and earthquakes. In "Pacific Rim," kaiju are classified by the Serizawa Scale, which fans believe is named after Dr. Daisuke Serizawa, the scientist in 1954's "Godzilla" who came up with the "Oxygen Destroyer" that killed Godzilla.

The Serizawa Scale has five categories. The water displacement (or size), the toxicity level of their blood, and the amount of radiation the kaiju give off decides which category the kaiju fall into. Category I kaiju like Onibaba are no cake walk, but they're the easiest to fight and least destructive. Category V kaiju Slattern was the most dangerous monster the jaegers had ever faced. The scale is helpful in knowing what the robots are up against, but the bottom line is that all kaiju are bad.



The kaiju are different from any other lifeform on Earth, and not just because they're giant monsters from another dimension. Well, that's certainly part of it, but the kaiju are also created differently than any other creature because kaiju aren't born, they're made. As Newton discovered in "Pacific Rim," the kaiju are grown as cloned body parts from a single genetic line instead of whole animals. The body parts are then sewn together by the Precursors to become whatever they need at the time.

That makes the kaiju incredibly versatile, malleable, and quick to produce. If the Precursors need a kaiju with two clawed arms, four legs and two heads, they can do it. If they need a kaji with one arm that sprays acid, they can make that too. Almost any creature they can imagine becomes real. The Precursors are like the Burger King of monster makers, because they always have it their way.



Now let's talk about some things you definitely wouldn't know just from watching the movie. The prequel comic and novelization of "Pacific Rim" provided details that filled in more of the background of the kaiju. For instance, the life of a kaiju in its native dimension (called the Anteverse) isn't all roses and sunshine. In fact, it's downright hostile. The Precursors don't just build kaiju and send them to Earth. The kaiju have to go through their own trials first.

In the Anteverse, kaiju are pitted against each other in combat to find out which are the strongest. The ones that lose the battles are killed. The ones that survive are forced into combat again until only the strongest and most deadly come out on top. It's a Darwinian tournament that means only the best of the best are sent to Earth. We should be thankful getting the cream of the crop if they weren't there to kill us all.



In our world, kaiju are really popular among fans of Japanese monster movies, which makes sense because giant monsters are cool. In the world of "Pacific Rim," the love of kaiju is cranked up to 11. As we saw in the opening montage of the movie, the kaiju made a huge impact on the environment, but also pop culture. Kaiju have influenced everything from entertainment to fashion in the near future, which only makes sense. Seeing giant crabs and lizards on TV is bound to inspire someone.

In "Pacific Rim," children play with action figures of kaiju and jaegers. People idolize the kaiju and tattoo them onto their bodies, like Newton. There are fashion designers who make outfits and makeup inspired by the kaiju. There are kaiju on TV shows and in movies, and the kaiju are even worshipped in temples made from their corpses like we saw outside Hannibal Chau's shop.



The kaiju have some awesome names like Leatherback, Knifehead and Slattern. It seems like every kaiju gets a cool name right out of the gate, and that's not an accident. In the world of "Pacific Rim," people don't sit around during an attack going, "What do you think that one should be? It's got a cool horn on its head. What about Hornasaurus?" No, the government has a database that generates and assigns names to kaiju the moment they're identified. It's not an original idea. Tropical storms are given names based on databases generated by international agencies. Government projects get randomly assigned names as well.

Of course, in reality, the kaiju are given names by the movie's designers. It's not much of a coincidence that Knifehead has a head shaped like a knife. The movie gives all the kaiju titles based on their appearance or traits, plus whether the name is cool or not, which is why all the names are great and add to the monster's mystique.



When Guillermo del Toro agreed to direct "Pacific Rim," he worked with the screenwriter Travis Beacham to create some new story elements. Several of the coolest moments in the movie came from del Toro, who had some pretty specific ideas of what he wanted to see. You can thank del Toro for the "live birth" kaiju scene and the flashback of Mako Mori to her childhood attack.

When we mention the live birth scene, we're talking about the part where a dead kaiju turned out to be pregnant and its baby burst from the body on a rampage. Del Toro has said the moment came from his desire to see a kaiju born on screen. The scene where Mori flashed back to her traumatic childhood watching the kaiju chasing her through the city was del Toro's idea of seeing a kaiju attack from a child's perspective. Both scenes were great moments in a great movie.


One of the biggest mistakes Earth made in fighting the kaiju was not realizing they were facing a coordinated threat. It was a mistake that cost them dearly. From the beginning, the defense forces (and the audience) assumed that the kaiju were just random creatures wandering through the breach into the normal universe. Each attack was treated separately from the others, so the military assumed they could eventually get the upper hand. Unfortunately, they underestimated the kaiju. Or, more importantly, they underestimated the forces behind the kaiju.

As Newton discovered, the kaiju were being sent to destroy Earth's population. Each kaiju was designed and built to overcome the weapons that had beaten the last ones. That's why the kaiju were able to smash through the Wall being built along the Pacific coast: that particular kaiju was specifically made to smash it. That's also why the jaegers faced kaiju equipped with acid and even an electromagnetic pulse, meaning both were designed with the purpose of destroying the robots. If left unchecked, there would have been no stopping the kaiju.



The world of "Pacific Rim" was more carefully designed than viewers gave it credit for. One of the biggest complaints came from people who would say, "Why didn't they just use nukes or missiles to stop the kaiju? Ha, plot hole!" Well, they actually did think of that and it was explained in the 2013 graphic novel prequel, "Pacific Rim: Tales of Year Zero" (written by Travis Beacham, drawn by Sean Chen, Yvel Guichet, Pericles Junior, Chris Batista and Geoff Shaw).

When the first kaiju attacked, the military launched all the missiles they had against it and couldn't stop it. In the process, the kaiju's toxic blood got all over the place. The only thing that stopped the kaiju were nuclear weapons, which destroyed the city. When the next kaiju attacked, nukes were used again and again. After a while, the governments realized they couldn't nuke the kaiju every time, because it would devastate the planet. Blunt force trauma was the best way to stop the kaiju without spilling too much blood. We're talking trauma in the form of giant fists belonging to giant robots.



As we said earlier, the kaiju are really toxic, and part of the reason is that (as Hannibal Chau said) their bodies are literally full of ammonia. That's not just something that makes them dangerous, but it comes from a branch of science called xenobiology that imagines what other life could be like. Some scientists believe that alien life could exist whose body chemistry is based on ammonia instead of water.

The idea is that ammonia is just as common as water in the universe, shares a lot of the properties of water and is a solvent that can support needed chemical reactions. No one has found a creature with an ammonia-based chemistry yet, and scientists debate whether it's even technically possible. In "Pacific Rim," it's not only possible, it's a fact. It helps the kaiju goal that having thousands of tons of ammonia crashing its way through New York City is a disaster for everything it comes in contact with.

What did you think of the Pacific Rim kaiju? What's your favorite kaiju? Let us know in the comments!

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