Think about the person doing it. Most times it is because they are lacking in something, be it attention from home or not doing well in school and feeling worthless. Most people that put others down, do it to make themselves feel good. I for one find that when some one looks angry and is saying mean things, it makes them feel worse if I smile and agree with them. I know its not true and their words are meaningless unless I give them power.
It never really bothered me tbh. I just keep it coming.
if you suck out the fun (for them) out of it, they won't have a reason diong it anymore. when they namecall you be totally calm and smiling and answer with witty short answers that will totally leave them speechless and they won't be able to bully you anymore. for example if they call you chicken, make the sound of a chicken and tell them "i'm a spring chicken not any chiken!" they will be like wtf! they will be totally discouraged to continue. they tease you as long as they see you are hurt and stressed by it... .