Your coworker's behavior is extreme, but your response shouldn't be. It is not your job to manage your coworker's interactions with others, and your manager alr

Your coworker's behavior is extreme, but your response shouldn't be. It is not your job to manage your coworker's interactions with others, and your manager already seems aware of the situation. Instead you have a responsibility to yourself as well as your team. You should empower yourself to act on your beliefs. It's telling that none of your five options include speaking to your coworker or trying to enact any change yourself. If, for example, your coworker begins to belittle someone else once they leave the room, you could say something like: "I don't think that null-reference exception makes them an idiot, but that's why we have code review," or "...perhaps we should have code review," or "...perhaps you could show them how you have handled a similar problem in your code, so we could learn from it." When you interact with your coworker, use professionalism as a tool: keep the topic relevant to business and remain as unemotional as possible. If you start to become emotional or if your coworker becomes emotional slow down what you are saying to give yourself time. You can also repeat what he or she is saying, in order to confirm or mirror it. If you keep it professional no one is going to blame you. Obviously you can get away with much worse, but you need to indicate to this person that it's not ok to talk that way around you. If you're feeling that way and your manager is feeling that way, then other people probably are. If you act professionally, you will give your coworker a dignified way of changing their behavior. Everyone, especially management, will want to avoid drama; but that doesn't mean you should let this person do whatever he or she wants. Right now you're enabling that behavior. Finally, you should think very carefully about leaving your job because of one other person. That is a major life decision you are making, all because of one jackass. What are you going to do at the next job if you don't like someone? I would try to at least exert some influence yourself before changing your entire work life.