What can I say to the guys that bother me without being too rude?

Every single freaking day when I’m in lunchtime at school,when I always walk past these group of rude guys,they always make fun of me and laugh!The worst part is that I don’t even know them!!!! One time my class walked past them and one guy was like “Big nose at 3 o clock!” it hurt my feelings!All you guys on fluther tell me to stick up for myself and be confident but it’s really hard to do if your dealing with a whole group of guys! I wanna yell at them or punch them but I wouldn’t want to be known as a mean girl because that is the opposite of what I am.What should I do this time? Should I tell a teacher?Should I keep trying to ignore it? Deal with it? What?