Worst is an overstatement. Arrogance is better.
It's funny – thinking back to all of my teachers, I find it very difficult to find a "bad" one. Education was like candy to me. If a teacher wasn't totally clueless, my overall impression, years and years later, seems to be very positive. I love teachers. Plain and simple. I wanted to be their best friend.
For the worst, I won't name names. And I don't actually think he was terrible. This was in college. Arrogant. Head of the department. And as such, he could "get away with it." Whatever "it" was. For some reason, he rubbed me the wrong way from the beginning. Seemed to inspire me to challenge him at every turn. His prep was half-assed and lazy. You could tell he was brilliant. But it's hard to take a man seriously who comes to class in really old jeans, and then proceeds to lean back in a chair with his legs way up high on the table, all class, every class. Crotch shots, for those of us sitting near. For someone at the top of his game, he didn't inspire. So sad. Like he needed very much to cling to and convince himself of his own mystique. His own TA's, assistant and adjunct professors were amazing in comparison. They're certainly having brilliant careers now.
The thing about academia is that so many are researching, writing grants, kissing up, publishing or perishing – as it's said. Those wonderful people who invest in their teaching – wow. I was lucky to encounter them throughout most of my life. Including award-winning physicists, Pulitzer Prize winners, and celebrated authors.