"What is a Kaiju? It's something very simple to say, but hard to describe... you just sort of know."
A Kaiju can be of any shape or species. Instances of blobs, insects, plants, rocks, lizards, robots, and even nanobots. What truly defines a Kaiju is the unstoppable force of nature they are.
The few biological trains kaiju shares is their radioactive nature. As a natural radioactive sponge, they will emit a small amount, but long term exposure is nothing to fear since the type of radiation emitted is not harmful.
Genetics and Reproduction
There are some lesser Kaiju who have paired into couples, but most produce asexually through laying eggs. One may think this will cause an explosion of Kaiju, but should an Asexual Kaiju lay eggs, only one egg will hatch to replace the kaiju who perished, the others lay dormant, waiting for their turn. These children are clones, genetic copies, and they will carry on the memories of the previous Kaiju, a sort of memory transference if you will. It's not a full consciousness, but just a sort of information dump of the important things... like who killed you, where they killed you, and how mad were you when you died.
Growth Rate & Stages
Kaiju grow at an exponential rate that's determined by how much radiation they absorb. There is a "stable" size that a Kaiju can achieve with ambient solar radiation, but when they move into a location with high radiation, their body absorbs it and increases its mass.
Ecology and Habitats
Kaiju can be found around all parts of the globe. Kaiju are super specialists and often adapt to their environment, no matter what it is.
Dietary Needs and Habits
A Kaiju mostly eats radiation. It's not actual consumption, but more like a plant's photosynthesis. This is a major Kaiju identifier. Most of them enjoy the instinctual nature of eating, but they do not NEED to eat in order to survive. I personally took residence near some old nuclear testing grounds, and I'm fully energised. I figured in 200 or 300 years, the area will be cleaned and I'll move on to another spot.
The biological cycle is unique with Kaiju, as all Kaiju are unique.
The Kaiju social structure is something that can be broken down into 2 phases. 1. Sleeping 2. Fighting That's really it. It wasn't until we moved to Monster Island that the Kaijus got any real sense of fun or see that there's more to life than using a Kaiju as a soccer ball.
Since the awakening, Kaiju roamed the world, unaware of what their presence was doing to the newly inhabited surface. Most were unsure what to make of the humans, and they had fought back fiercely against any intrusion into their territory. None of their weapons hurt, but it's still sad when you're trying to be nice and everyone runs in fear... After the Big G-man himself caused enough of a scene, the humans decided to help keep us occupied and entertained... and try to keep us from running amuck. When the XIlliens released their bioweapon on the humans in the form of a virus, they were no longer able to maintain Monster Island. The staff made arrangements with various cities to allow displaced Kaiju to move nearby.
Uses, Products & Exploitation
The biggest use of Kaiju from humans is our ability to absorb radiation. I know a few who eat spent nuclear rods for snacks. We're also asked to help with demolitions, undersea recovery operations, and pretty much anything else. At first, when the Kaiju were fighting the humans all the time, we didn't really know the damage we were doing
Over the years and many battles, the Kaiju evolved into a battle-hardened species. When first discovered, they often looked weak and pliable, but through many defeats, each successive generation adapted to its defeat and evolved resistances.
Geographic Origin and Distribution
Kaiju are smarter than they let on. We have our own language, and can pretty much understand most humans. We have a hard time with our lips though, so we rely on performance art to communicate... but oftentimes, the message gets misread and then we have to dodge hellfire missiles and tanks when all we wanted to know was when the next Mega-man game was coming out.
Perception and Sensory Capabilities
A Kaiju's sensory traits vary based on the type of kaiju they are. If they are land or water, then they will be more sensitive to vibrations and use a sort of sonar-based system, while others may model themselves after various insects and humanoids. There is one thing that ALL kaiju are capable of, and it's the ability to alter the density of their atomic structure. For example. I am a Kaiju of 59m (193ft) and 3200k (7054lbs). Now, for the math people hitting the calculator, you know what I'm about to say. the MASS of a kaiju doesn't really change. We can grow and shrink at will by expanding and contracting the space between our atomic structure... it's a perk of the radiation. Think of pufferfish. All those science articles about how we're breaking the mass/weight boundary... have you not noticed we don't sink to our ankles in your cities?!? We're mutated and irradiated, the overexcitement of our atomic structure spread the distance out, thus allowing us to grow. The ONLY ONE to have been shown on camera to do this was... Minnella. This ability to grow and shrink our size, but not alter our mass has lead to some hysterical conclusions with humans! A Kaiju can go on a rampage and just... vanish. People think, "Oh they dug underground...." How do you think we do it? We shrink down to about a Meter and just sink. the density of topsoil is just like wading around in the mud to us... we can just push it all aside, and not cause too many tremors, then when we want to show up, we just explode out of a mountainside for dramatic effect! So, I can be 59m tall, 5.9m tall, or 1.5m tall so I can fit into the stores and get my pre-orders. When smaller though, a Kaiju must be careful, because each step can sink through the human construction.
Symbiotic and Parasitic organisms
Some Kaiju can be parasitic. The Big G man himself fought an alien who wanted to be wayyy to close to him. No means No.
Civilization and Culture
Kaiju Management Department is a world organization funded by every country. It's mission is to capture and rehouse rogue Kaiju.
Most Kaiju are asexual and don't see other kaiju as anything more than a competitor. Each Kaiju has its own sense of style and beauty.
Kaiju are asexual by nature. There are a few instances of gender, but a secret Kaiju fact is that we are able to choose a gender and produce eggs with a mix of 2 partner's DNA. A common trope is to refer to Kaiju as "He" when it really should be "She" since most Kaiju lay eggs!
It's uncommon for Kaiju to date.
It's even more uncommon for Kaiju to be in a relationship
Average Technological Level
Kaiju have no use for technology, that being said, they are smart and able to use whatever humans can.
Major Language Groups and Dialects
Most Kaiju communicate through rudimentory growels, roars, or violence.
Kaiju have been seen through all of human history, but they often slumber until there is a reason to awaken. A normal kaiju wakes to feed, breed, or fight. The fact that multiple Kaiju are awake at once is the result of extensive nuclear testing in the '40s and '50s with extensive radiation in the atmosphere. The creation of nuclear reactors only exacerbated the situation, as the ambient radiation awoken local Kaijus who felt compelled to feed off the reactors. It has been discovered that Kaiju are a way to process harmful radiation, and after decades of work, Humans and Kaiju learned to understand each other and adapt to each other's needs. From all the testing and the ambient radiation levels, the Kaiju can't hibernate until the ambient atmospheric radiation is below a certain point. To save humanity, Monster Island was formed and is the main dumping ground for toxic and radioactive waste. The Kaiju have free reign of the island, and some of the more intelligent ones began working with humans to help understand the two cultures. As a young Kaiju, I was one of the first ones to join and that's' where I learned about all the neat human things you have!
The Kaiju species are considered endangered, as there are very few active Kaiju. It's not known how many are still hibernating, but Monster Island was formed as an ecological sanctuary to house various Kaiju in a safe environment and keep them, and humans from harm.
Most average Kaiju are bi-pedal. Some are Insectoid, robots, and other various shapes, but they often average the same height during a fight.
Body Tint, Colouring and Marking
Very rarely are there two kaiju that look alike. Should any Kaiju seem to match perfectly, than one is surely a robot, alien, or robot alien and will come to kill us all.