#this character (and consequently the beginnings of this worldbuilding) has existed since like 2011.

[thiefking]

☝️🤓 she's a parasitic alien species who can eat anything. the life cycle of their species is to send an egg to a planet, hatch and immediately eat their egg and then any living creature nearby to use it as basically a skinsuit, then continue eating various creatures until they determine the planet's dominant species, at which point they eat an infant/juvenile member and replace them entirely in their family (you know like parasitic birds who lay their eggs in other birds' nests) to be raised as a member of that species and allow it to go undetected as an alien since it's been raised with all the social cues and body language it needs to blend in. the true body of this parasite grows as they eat but they can make themselves into a dense, hypercompact egg-shaped thing and they spend most of their time as a juvenile in this form. they can eat without unfurling too, but it's hard to fight, so the only time you ever see them unfurled is either when they're freshly hatched or when they're in full on attack mode. they are also seemingly completely indestructible when they are compact and STILL extremely hard to kill when they unfurl their bodies since their primary diet is eating rocks, minerals, and metals, and they can reconstitute them to reinforce their shell*. they will eat more and more and more as time goes on and their true body will get bigger and bigger and bigger and eventually when they're big enough they know no one can stop them, they unfurl semipermanently and start eating their very host planet. when they're done and now the size of an entire PLANET, they fly off into space to go find a mate and the cycle begins anew

i wrote too mjch the rest goes under the readmore.

* some theorize that the "shell" is an exoskeleton, and others argue that this is just their skinsuit thing again and it's more like a suit of armor that could theoretically be taken off. there's evidence supporting both viewpoints. since no one knows for sure, they just play it safe and call it a shell— and either way it's still 100% certain that they produce it themselves. it's still unknown what their shells are actually made of, but it's likely that it at least somewhat depends on their diet. they eat their own egg because the eggs have nearly the same strength as their parents' shells and allow for immediate protection. if you manage to find a hatchling perhaps you'd be able to simply stomp on it and kill it...

they are HIGHLY dangerous and because they're also extremely rare, there's very little research on them. no weapon has been seen to penetrate its shell, they're highly heat-resistant, they're seemingly borderline magic-immune (with the one caveat being they are only any good at DEFENSIVE magic, if they even learn magic at all)... it's hypothesized the only way to kill one is by having another member of the species eat it, but that might just make an even bigger problem... they haven't tried everything but there's only so much they CAN try with a species so rare and volatile. so um, generally the protocol if you discover one is to immediately launch it into space. which also doesn't kill it, it just makes it harder for it to get anywhere because they only develop the necessary appendages for space travel when they're planet-eating big. preferably you find them when they're still tiny and weak, because if they are then you have time to experiment and see if you can kill it before you call it a loss and launch that thing into and then out of orbit, but if they're big enough to be a danger to you then you just launch em

the one good thing is that their species prioritizes a BIG planet over a SMART planet, and their intelligence depends heavily on what kinds of brains they've eaten and how they're raised. they're highly adaptable, but only to the point they need to be and no further. if they land on a totally lifeless planet, they just start eating it and don't even bother with a disguise. their species values Bigness more than Intelligence and the parents try and get their eggs to land on big planets to make sure their offspring is gonna be popular. this is a point in favor of the "suit of armor" theory, because if they're perfectly happy on unpopulated planets, that suggests that its imitation/skinsuit behaviour is just the parasite using its armor ability in a different way with a different material. however, they've also been observed seemingly partaking in a molt— this was exactly once, ever, and it's possible that it was simply eating another member of its species that happened to land on the same planet, but it was indeed observed to be hiding away in a cave eating a piece of parasite shell. this is a big point in favour of the exoskeleton theory, as is the insectoid appearance of... Some... of the parasite's body, but "suit of armor" theorists argue that it could just be hermit crab-like behaviour of moving into a bigger shell and eating the old pieces to recycle them into its new shell

the problem is mia did not end up on jupiter like she was supposed to. mia's egg missed it and landed on earth. and now she has human intelligence. and then she got found out by The Magic Government.

this is kind of an ethical conundrum for them because launching the planet-eating worm into space when it is Literally dumb as rocks is a pretty sensible solution when you don't know how to kill it. but THIS one has human intelligence. and it is also rather big already. and it seems like a rather important magician has already taken a liking to it...

a lot of them still thought killing it would be best, but others brought up that its unusually high intelligence means that first of all it would fight back. and secondly it can probably be reasoned with. and it would make a FANTASTIC weapon and tool, and also our much more common problem is the gates, you know, those holes in the universe that are invisible to most regular people that when touched will transport that person to a completely different place in spacetime and are responsible for loads of unexplained disappearances and are an incredible nuisance? and presumably because their entire life goal is blending in and eating a planet, these parasites can smell gates and tend to Instinctually Eat Them because they're a rare edible form of raw magic which these things don't tend to naturally produce?

and so she is offered a deal. they won't launch her into space or try to kill her IF she lets them put a leash on her to use her as a gate-sniffing dog and/or living weapon. she begrudgingly accepts

the main way she is nerfed is by her own storyline: it's all about magic and she can barely use it. she has crazy hp, atk, def, and sp. def, but her sp. atk is like nonexistent. best she can do is status moves. magic resistance kinda goes two ways. also, while she can eat gates, she can't eat or digest any non-solid magic, which is... almost all of it. it would be like trying to "eat" electricity. so a magic shield offers complete resistance against a long distance stomach acid spray attack. she COULD just swallow them whole and wait for them to get too tired to maintain their shield and they'll get disgested as soon as it breaks, but if they can teleport, which is an exceedingly simple spell... it's a nonstarter. plus, eating them alive would give them a chance to see her insides and potentially discover a weakness to exploit if they have enough magic left they're willing to risk staying in there a little longer to explore. not worth it. her job involves eating gates so she actually has (comparative to other members of her species) loads of magic so she IS capable of using it & she's pretty damn good with making shields of her own, but in fights against magic users (in other words basically all fights) she's relegated to a defensive role and she kinda hates it & often feels more than a little useless

If your OC is considered over-powered for your setting, what is it that sets them apart from the rest? How do they use it to their advantage? How does it impact them?