In my 7th grade math class, I got busted writing a story about my math teacher having sex with dogs and having a penis. Some of the other students were named as dogs who fucked her. I remember there being rape, castration, and some deaths. She snatched my notebook away from me, I got up and tore what ended up being half the page out the notebook and shoved it into my mouth (which I was already thinking about because of the recent episode of It's Always Sunny where Mac eats a contract). Unfortunately, enough of the story remained to get me sent to the counselor, all of my writings and drawings confiscated, and threats of expulsion, psychiatrists, and all of that bullshit.
I spent a significant amount of time in school between 3rd and 10th grade in trouble for my writing and drawings.
I think my favorite year of actual writing for school was 10th grade (the first year in senior high school in Idaho) where during the first month of class I gave an oral presentation on why total human extinction would be a positive thing...and finished the school year with a final course capstone book report on Silas Marner where I wrote something completely insane about him being a demon-worshiping pedophile.
My writing was pretty good. I managed to get through the honors classes in spite of the content. The content part just made me a familiar fixture in the counselor's office.