From what I gather the zoids are mechanical organisms with a living zoid core.
Organoids are small zoid-like creatures with the ability to temporarily fuse with a zoid's core. This can boost it's abilities or even repair a dead or damaged core amung other effects.
But presumably if cores can die then that means new cores have to come from somewhere otherwise inevitably you wouldn't have any zoids left. So where do humans get zoid cores from to build new zoids?
There were some zoids that were wild too I think in Chaotic Century as well as in the Zoids Legacy game, but I don't recall any in New Century. Am I to infer that perhaps zoids may not even be built by humans, but rather be more like domesticated wild animals?
Organoids seem to be associated with ancient zoidians and only seem to show up when they do. I would presume this must mean ancient soldiers probably created them and with the ancient zoidians almost all gone new organoids simply can't be created any more. They also created zoid eve and subsequently zoid cores too, but with the prevalence of zoids and rarity of organoids I have only two hypotheses here. Either new zoid cores are still being produced somehow, or zoid cores being sheltered inside of zoids bodies and being able to be revived by organoids has made them more resistant to being wiped out over time as compared to organoids.
Basically, yes. None of the anime series go into much detail, but the cores are definitely alive and sentient in all of them. In the Battle Story, and maybe some of the anime, these cores are taken from "Wild Zoids", creatures that have evolved and bred naturally without human intervention. I don't remember proper Wild Zoids (野生ゾイド) appearing or even being mentioned in any of the anime (or Saga series), but there are occasional mentions of "wild Zoids" (野良ゾイド) that should have been translated as Stray/Feral Zoids (military Zoids that have lost their pilots and now act on their own). Some people will tell you that Organoids are Wild Zoids (based mainly on appearance), but supporting materials confirm that the Organoids were small Zoids created by the Ancient Zoidians. Then again, it's possible that
all Zoid Cores in Chaotic Century were created by Ancient Zoidians - see below...
If the Zoid Eve dies, it doesn't just kill the Zoids, but the Ancient Zoidians as well. I would assume by this logic, that it came first. Unfortunately outside of the anime/manga (which is vague at best) the Eve barely gets any explanatory mentions.
The anime OS seems to be kind of a bastardization of what Organoid Systems were supposed to be. IIRC they were functionally like the sleeper systems in the anime, allowing Zoids to act remotely. Several low-level Zoids also had these. On the other hand, the "Ultimate X" as it is is treated in the show (a Zoid capable of learning), in the original battle stories were wild Zoids. Which were, indeed, wild creatures whose cores were harvested for the machines we know today. The anime didn't go into detail about this kind of world building stuff so I just tend to equate Ultimate X = Wild Zoids. Wild Zoids were a force to be reckoned with for their natural strength and ability to act with or without pilot intervention.
Well... sort of.
Unlike the Organoid System in New Century, which is just a self-improving AI, the OS in the Battle Story is a system that "makes Zoid Cores abnormally active", increasing the Zoid's abilities but making it more vicious and difficult to control. Limited versions of the OS were used in Zoids like Rev Rapter and Gun Sniper, while stronger versions were used for the Blade Liger and Geno Saurer/Breaker. The ultimate example would be the Death Stinger, which is heavily implied to have killed its own pilot and started spawning baby Death Stingers due to overclocked survival instincts. An "Interface" (shaped like Shadow) was later discovered and used to create slightly weaker but more controllable Death Stingers. The OS was also used to rapidly increase the numbers of rare Zoid Cores (including Wardick and Death Saurer), presumably by making existing cores reproduce faster and/or in greater numbers.
As far as I can remember, the term "Ultimate X" was never used in the Battle Story. Instead, the Liger Zero and Berserk Fuhrer were "directly based on" Wild Zoids, making them more responsive and manoeuvrable, and were considered superior to Organoid System Zoids like the Blade Liger and Death Stinger. However,
all military Zoids (until Blox) used cores from Wild Zoids, and they were all capable of acting without pilot control (which is why Stray Zoids exist). Presumably the Zero and Fuhrer were just more physically similar to their Wild Zoid bases than most Zoids, or something.
As for the Zoid Eve... time to infodump all confirmed information about it!
- "The Ancient Zoidians used the Zoid Eve to produce many Zoid Cores, and by using those Zoids, we were able to create a world of limitless prosperity and potential." (Fiona)
- "It was believed that when the Zoid Eve ceased, all Zoids on the planet would cease as well. But we could not bring ourselves to completely extinguish the Zoid Eve's power. This is why Zoids continue to exist on the planet Zi." (Fiona)
- "On the other hand, by resurrecting the Zoid Eve and releasing its power, Zoids could multiply infinitely and flourish on this world once again." (Dark Kaiser)
- "Like an Organoid, the Zoid Eve has the ability to heal the wounds of damaged Zoids, but it also has the power to quickly resurrect damaged Zoid Cores completely." (Hiltz)
- "This energy... it's so big, it could only be coming from one possible source! The Zoid Eve!" (Doctor D)
- "You have to remember that the Zoid Eve is the fundamental source of energy for all Zoids." (Doctor D)*
- "Destroying the Zoid Eve will bring an end to all the Zoids, and the entire race of Ancient Zoidians will be annihilated!" (Hiltz)**
...and that's pretty much it, besides the constant reminders that reviving it will power up all Zoids (particularly the Death Saurer) and destroying it will kill all Zoids. Even the Anime Encyclopedia doesn't add anything useful (it also doesn't say anything about that ring around the Death Saurer in the final episode, unfortunately). As for the manga version, practically nothing is known other than it being the oldest and most powerful Zoid, the "mother" of all other Zoids (including first-generation Zoids like Hourai, Zeke and Fiona). There's not even any hints as to what it looks like, although it's probably not an immobile statue like the anime, since Hourai "hasn't met her in 300 years" and doesn't know where she is now.
(* The Japanese version of this sentence is more along the lines of "this must be the fundamental energy source for Zoids", not "Zoid Eve
is the fundamental energy source and you should know that already".)
(** I'm not entirely sure destroying the Zoid Eve would
directly kill the Ancient Zoidians, and this quote is fairly vague. There's an earlier line by the Dark Kaiser - "The Ancient Zoidians would have perished without their Zoids, and you know nothing's changed" - which suggests that they just wouldn't know how to survive without Zoid assistance. If
all Zoid Cores were produced by Zoidians through the Zoid Eve (Fiona's quote isn't detailed enough to say for certain), they must have done fine without Zoids to begin with, so maybe it's equivalent to saying "humans wouldn't know how to survive without the internet". But I'm getting too far into speculation here...)
Wow, this post got humongous