Does a muslim have to change any of his/her natural beauty?

Is it ever obligatory on a muslim man or woman to change any part of his/her body ? (other than trimming the nails, moustache or pubic hair) For example, if a person has a natural hair which resembles one of the styles that the kuffar have, does he/she **have** to change the hairstyle or he/she can keep it because they have this style naturally? (One of my cousins actually had a natural mohawk (almost)) Another example, say a non-Muslim women do a specific kind of change to their bodies to excessively beautify themselves. If a Muslim girl is born with that kind of beauty (the kind which the kuffar try to mimic), does she have to change that beauty because that resembles the kuffar?