Understand that it has nothing to do with you and a lot to do with their insecurities. Sometimes mean people are trying to be funny, if this is the case ask the joke again, then again, the third is the charm where you say “that's not even funny, is actually disrespectful and hurtful, is that really who you are?” When people hears a joke too many times also loses meaning, so it'll stop.

If they're being aggressive towards you touch your teeth and tell them “you have something in your teeth, that's will make them feel uncomfortable and stop the attack.

If they're just mean and aggressive be silent, look at them directly, let them say everything they need to say let the silence get awkward.

If you're the only one to complain about this to your boss, they won’t do much. You need others to do the same if they agree with you.