Intro/Plot/Characters: Intro time!
Awesome, the ever popular, philosophical-esqe, mysterious first sentence. To be honest, I like these, but some work better than others. There is a lot of emphasis in this story about the relationship between Marcel and her Caterpie, but I'd venture to say that the bigger idea/theme is the horror of mental illnesses (in this case schizophrenia). Therefore, if you're going to do one of those overarcing, story sum-uping (Yeah, I made up a word, I'm cool like that), foreshadowing sentences at the beginning, it should be more about the fact that Marcel is coo coo for Cocoa Puffs. The rest of the intro kind of covers how she was a serial killer and the police had been looking for her. Oddly enough, you don't get into the serial killer aspect much, but that comes next.
When a life meets another life, something will be born.
Now we can talk about the plot. Alright, so your main character suffers from schizophrenia, and I'd like to say right off that I am a big fan of mental illness driven plots, and the way you make her super paranoid about everything. However, I would've liked you to explore some of her other symptoms. There are all kinds of places you could go with this, and absolutely HORRIFIC possibilities. For example:
That is a piece of cloth embroidered by someone with schizophrenia. It frightens me. Imagine her slowly becoming crazier and crazier and talking like THAT. O_O Also, the beginning of your story seems to hint that there's going to be a lot more serial killing going on, and it's kind of glossed over, which is weird since you build up to it. However, this is a Caterpie story, and for an easiest rank story, you've done quite well. I just thought I'd say that before I continue nitpicking. Okay, you know your story is good and that I like it in general? You sure? Cool, let's move on. Next, people with schizophrenia tend to have odd patterns of speech, which I didn't really see associated with this character. I did like how you went into her background as a child, but it's never REALLY explained why she's killing people, other than that she considers them threats to her Caterpie. Here's another thing to think about; wouldn't someone who was crazy be really bad at covering their tracks from the police? How did she go uncaptured for so long? I'm going to stop now before I hurt myself/you/whoever does grader wages.
Detail: Detail was pretty good. You described things differently (and in my opinion better) than many people do. For example, Caterpie's six scales were cool. I never hear anyone mention things like that. They usually go for color, maybe shape, and leave it at that. You stepped things up a notch. In addition, you had some really nice detail describing Marcel and Ms. Teacher. To be honest, the Ms. Teacher thing annoyed me a little bit, because it reminded me of cartoons, like Power Puff Girls or something (Townsville, Dr. Doctor, you see where I'm going with this). I think it would've been better to give her some kind of generic name at the least (or take things a step further and make her some kind of reference to another serial killer story- MS. STARLING ANYONE).
If I had to think of something you could add, I would've liked to have some more sensory details (in this case touch, sound, taste, smell), and also some more information about her emotions. We know she's scared and angry that someone might hurt her Caterpie, but you could delve deeper into her confusion and constant fear that people would hurt her and her loved ones. There's a lot of angst buried deep within this. I KNOW YOU CAN FIND IT.
Okay, first lesson: active and passive tenses. The active tense would be if you had said 'His teeth came together and showed when he grinned'. What you're using, with that 'was' thrown in there, is the passive tense. Passive tense is usable (or we wouldn't have it), but it's kind of slow paced, boring, and in this case, clashes with the active tense in the first part of the sentence. It'd be better if you made the whole thing active tense.
His teeth came together and was shown when he grinned.
'Hold' should be 'held'.
The girl’s arms were hold behind her as the cop walked the girl to the cop car.
'Or' should be 'nor'.
Either the victim was dead or the person was in such shock from the idea of death that not a word could be spoken or could the moment be recalled on.
Three things: First, you need a comma after 'crime' and before 'lied', because saying it's the Caterpie is clarifying something in the middle there n' there's a technical reason why it does that, but just in general when you're describing someone and then put the persons names, you do commas like that. Second, 'lied' should be 'lay'. Lastly, why is the ground in an alley tiled. X_X Baha. I've done things like that too, and I suspect you're thinking of the ground being laid with bricks or something? I dunno.
her partner in crime the Caterpie lied there on the dirty, tiled ground.
'Dampen' should be 'damp'.
Not a hand would gently pet his dampen skin.
That verb doesn't really make sense here, since it's something he's doing to his body. Inched would work.
He crawled his six scaled body around the corner.
Maybe put the word 'such' before 'as'.
Anymore and he would do something crazy as run for that police car that just made his heart jump.
'Straighten' should be 'straight'.
Ms. Teacher stood back to her straighten posture and crossed her arms.
'Nonsense' should be one word and there should be a comma after 'nonsense'.
That it was nothing more than non-sense that the teacher wasn’t doing anything for her daughter.
I think instead of 'smart' you should put 'intelligence'.
Inside her mind, it took a lot of smart to be able to pet her Caterpie.
'Know' should be 'no'.
“Oh know...” something had clicked for Marcel.
Alright, you've got some weird sentence structure thingies going on. First, one of the best ways to tell if your writing sounds weird, is to reread it, sometimes out loud, so you can hear if things don't make sense. Also, there are places in here where I feel like you pulled out a thesaurus and picked out random words to replace more common words. Different words have different connotations, and that can make the meaning of a word way different than what you thought it meant. I would recommend using words that are more familiar to you. Even though they might not be fancy or sound like something you'd find in an Ayn Rand novel, they're often better choices to use, as they sound more natural. :D
Length: Your story is three times longer than the minimum length, I would say overkill, but I actually think it's kind of cool. GOOD JOB.
Outcome: Caterpie... most definitely captured. ENJOY.