I've had a couple of teachers who were real pricks to me throughout high school.
One of them was my 11th grade Latin teacher. This guy was the biggest prick ever. We never really had tests or anything to assess grading, so he basically made up grades for people. It was weird how he did it because people who sucked up to him received the best grades, then the next grading semester, he would give them F's. He was an old perv so of course, he gave all the girls in the class A's and B's. I always had conflicts with him but always managed to squeeze out a C. The reason I would have conflicts with him is because he would make fun of people for their ethnicity. While it's funny once in a while, it gets really old when he continually made fun of me and my friends (who are all Polish) about how we're stupid, put screen doors on submarines, and other jokes that are just really annoying and stupid. I would always talk back to him and give him snide remarks, which always caused me to get put on his shit list. However, one semester, I told another one of my Latin teachers that I was close with how much of a douche my Latin teacher was. That teacher (Mr. Tedeschi) talked with my teacher (Dr. Carroll) and basically said he was teaching his class wrong and that I told him everything. The next day of class, Dr. Carroll came in, took me outside of class, asked me what I told Mr. Tedeschi. I refused to tell him, so he gave me an F, then announced to the whole class that I was failing. Fucking asshole.
I would see him from time to time afterwards and he would act like I'm a fucking total idiot. He would ask me if I was going to college, then when I said yes, he would go "Oh, which community college are you in?" before I could even answer the question. I actually went to one of the best Liberal Arts schools in the country, and this guy thought I was a complete moron. Fuck him.
Another teacher that I absolutely hated was my 10th grade Geometry teacher. I admit that I suck at Math & Sciences and they have never been my strong suit. However, this teacher was a horrible teacher, and on top of that, a huge black female who smelled like shit and always played the race card. When I asked her once why she wouldn't set up after class tutoring for me but did it for another black student, she went off about how I was "ignorant and don't understand what black people went through, blah, blah, blah." I just wanted some tutoring, not a lesson about how I'm supposedly ignorant to the plight of Black Americans. She always explained things too fast, didn't like to repeat herself, and once told me to "figure it out yourself" instead of simply explaining it to me. She tried to make a classroom where the students would learn through collaboration, but the problem was that none of us knew what was going on, so it failed miserably. Half of the class was in my situation because of this. So basically, I just barely passed her class (60.5% cumulative avg., just barely) and then she tried to change my grade after they were submitted because I told her she was the worst teacher I ever had. She then said I was racist and wanted to have me suspended from school. Fucking bitch.
I've had some other bad teachers, but these two were the worst, by far.