I was working for a company that had about 24 people at the site that I was at. There were two people out of those that had bad attitudes toward me - my immediate boss and someone I will describe as a metalworker. There were also two people I didn't think much of, but they had nothing to do with the two mentioned above.
I was the 'network administrator', but my real portfolio was training, software support, report writing, programming, and general IT fixit. My 'office' was the server room, where we had running hardware, modems, software, media, etc.
I tended to be a bit remote emotionally from the other people there - my mind was really elsewhere and in my own mind I should have been programming. The early 1990s economy was kind of miserable, so you took whatever you could get. I was also concerned that the top management had dropped in six weeks after I started to tell us they had a wage and hiring freeze, and there might be some layoffs.
The former person in my role had done almost nothing - at least nothing but get in spats with my boss. She (the predecessor) quit coming in during working hours, and did all her 'work' after dark. In the early 1990s Windows was at the 3.0/3.1 release, and the only instance of it I could find in the whole place had huge Solitare game statistics.
Three things became apparent as I continued to work there - first, I was 'cleaning up the unfinished business' - getting all the computers with the same version of operating systems and software. Second, I received all incoming hardware, and upgraded and expanded the PCs and other resources as circumstances dictated. Third, I had 'no fear' - I was writing programs to log data from National Instruments DAC boards, an area I had never touched before. As such, I became somewhat of a 'power center' in the organization - and this was a problem for the boss in part because he wasn't all that computer literate, and the 'metalworker' because I appeared to be rude. 'Rude' wasn't from saying things, I tended to be somewhat of a recluse, and really didn't have anything to talk about with him. He was also the only person in the organization that didn't have a computer, and could care less what I did for anyone else.
At any rate, the personal chemistry between me and these two individuals deteriorated over time. I got the feeling toward the end of this, in particular, that they were trying to get me to quit. While I really wanted out, I wasn't leaving until I had another job, unless they fired me.
For most of the other people in the group, I was more and more approachable over time, and in particular got along with most of the women. Whether this was part of the irritation I don't know - I certainly wasn't dating anyone or even particularly cozy while at work. The boss was someone that didn't have much patience with whining, and some of the people there were being overworked. While I might have been a bit distant, my conversations with people tended to start and remain civil. Therefore I might have been 'less bad' than other co-workers.
However, I was also not 'striving' in any sense - none of my conversations with anyone were focused on career advancement, pay raises, perks, or anything else. However, I did have a habit of coming in late, and generally working late, due to traffic. This eventually produced a written reprimand - which didn't much mean anything to me one way or another. While they were writing me up I was performing regression analysis on their monthly production, figuring where and by how many people they were short. Perhaps I was perceived as 'not taking anything seriously' - probably true, but on the other hand I wasn't careless.
I respected my boss and the 'metalworker' for what they did - I had no doubt they were competent. We had goofballs in the company, but they were on other planets as far as I was concerned. Overall the group was tight, good at what they did, and making their best effort.
The 'metalworker' got more and more assertive toward the end of my employment - in one case he blocked the door so I couldn't leave - right in front of the overall plant manager. The only thing I could imagine was this guy wanted to trigger some sort of physical reaction or outburst. I had no interest in fighting with him or anyone else.
This guy had a desk in one of the offices, and I got moved from the server room to this same office. Shortly after that someone, or something, broke his radio and he was convinced I was responsible. I didn't even know he had a radio until someone said I'd broken it. About all that could be said from this is that someone was on a campaign. I hadn't planned to make a career out of that company, in fact I had been seeking work for a year. I was one of many in a quarterly downsizing - I had just managed to find another job and didn't miss a workday.
Point: you may have something this other person wants, and it may be nothing more than street credibility. He may either want the role you're in, your background or experience (which for some reason he could never get), your particular work assignment, or the respect you're getting from your peers. You might be doing something irritating (like striking up conversations with women, or coming in late, or doing things that management didn't approve of first) and 'getting away with it' compared to others that can't.
My (now ex-) wife had gone to a fairly highly prestige university. Her boss had completed her degree in a somewhat less prestigious school. The two of them had a cat fight, and the boss told her something about how she (the boss) had never had a debutante party or whatever - she didn't rank. In the case of my wife, this would have been a scream - I don't think their family held parties at all during the time she was a teenager or young adult. In short, the school was confused with the social circle - she was in the former, and miles away from the latter.
The best thing to do might be to figure out what is yanking this guy's chain. If he can't talk to you, other people might be able to drop hints. Some of it may be pure incompatibility, there might also be possible to 'meet in the middle'. He may have a misconception, and you may be able make some clarification that will help him settle down. The best route to take is through others, see how third parties are reacting to this relationship.