In my office, we would take it to the supervisor first. If that didn’t solve the problem, then the manager. If that didn’t do the trick, the petition and the deputy director might work. The water pistol, however, would get us in serious trouble.
Unfortunately, it is YOUR responsibility to get along with others. Anything negative that you do, aside from simply pretending the other person doesn’t exist unless it is work-related, can be seen as YOUR inability to get along and to work as a team. In other words, it can backfire and leave a black mark on YOUR record.
I would talk to the supervisor (everyone, that is, not just you), then the manager, then shun him. If everyone shuns him, eventually he will correct his own behavior or look for a job elsewhere. And that entails not making eye contact, not saying hello or goodbye, terminating a conversation and walking away if he comes over to join in, turning your back on him, and a host of other things. Just remember, don’t let it interfere with your work-related interactions, because, again, that will backfire on you. You were employed to do a job, whether you like the other employees or not. You don’t have to like the people you work with and there is no law that says you have to socialize with them either.
Despite the fact that I get along with most everyone in my office, there are persons I won’t have anything to do with and I take every break and lunch alone and have for over 20 years. I am, at heart, an introvert, and I can only recharge my energies when alone. I could probably improve my relationships if I shared breaks and lunches with someone, virtually everyone else in my office pairs up for these activities, but I wouldn’t enjoy it, so I don’t bother to try.