Let's see...
There was the assistant professor who told me that I should drop his class because if I didn't, he was going to fail me because I was not a mechanical engineering major.
There was the clueless TA who once started off a recitation section by asking, "Do you have anything in particular that you want me to cover today?" The prof had just introduced a very difficult concept in the previous lecture, so we all asked the TA to cover that. He said, "Okay, that's what I will NOT talk about today." I walked out on the spot and never went back - I sat in on a different section for the rest of the semester.
And my favorite: I had a professor who once wrapped up his prepared lecture with 5 minutes left to go in the hour, so he said, "I've got 5 more minutes, so I'm going to talk a little bit about my current research." Nobody listened or took notes because it wasn't on the curriculum. Nonetheless, he put it on the final!
Profs weren't supposed to put anything on tests that wasn't on the curriculum, but he justified it by saying that he'd covered it in lecture, so it was fair game... we all got burned.