er, was that a joke? Would you rather be a chav or dodgy looking greasy haired beggar?
It's not a question of what one is (or would want to be) but of how one is talked about by other people. 'Dodgy-looking greasy-haired beggar' is a description, i.e. it would help you to recognize the person concerned. 'Chav' is merely a term used for insulting or abusing someone on the basis of their perceived class.