I Mustache You A Question, But I Will Shave It For Later!

I mustache you all you a question... But I will shave it for later... Right now, I want you to answer my riddle! (leave a comment below about what you think it is, and I will try to reply if you are right or wrong as soon as I can) Here it is.... 'I am brown. I have a head and a tail, but no legs. I have seen the world, getting passed on by many a few. You do not think much of me, though if I grow in quantity, I am much more than I was before. What am I?'