Whats a good comeback when 3 teenage girls constantly make fun of my name?

My name is raven and these three girls make fun of my name all the time.. that doesnt bug me what bugs me is that they think they are cool always doing it..its getting old now because they have done it for a year and ignore them so that doesnt work anyways so what i'm basically asking is how could i get them to really just shut up..... whenever they see me or talk about me they always say hey look its raven CAW CAW CAW ahahhaha wow what a stupid bird and crap like that..... any good comebacks?