How to handle it depends on the work environment.
My job just has the store owner, so I don't have an HR department or anyone breathing down my neck to do or act a certain way. I'm a key holder, so I tend to close the store at night so that the owner doesn't have to come down or be there. None of my current coworkers would be mean, except one but she just gets cranky for no good reason so I give her food and she feels better. But we can be mean to new people who's behaviour we've found unacceptable, and only when telling them they need to stop and having them ignore us.
So that's something I'd look at first. Has my behaviour been poor lately? Have I been unjustly mean to someone, or too lazy (not much of a problem since we don't really care and on really slow night can take turns watching tv), am I doing something wrong?
If no, and they're just a jerk then ******** 'em. At my job I'd see who else they've been a b***h. Anywhere else I'd make a formal complaint. If it's Row, then I'd ignore and try candy later. New person, ignore and avoid (because I get to do that) and if I'm not alone we'd try to make the owner fire them. He's very nice though, so it's hard.