A tatoo is not just a personal, but psychological understanding. When you get a tatoo of something, it says something about you to everyone that sees it.
First You have to get it because YOU want it, personally I think getting a tatoo of a dragon is a bad idea(i'm not bashing you), but if you like it, it doesn't matter what I think. it's not my body and I am not the one who has to live with it for the rest of my life.
Second, if you have a tatoo you really like, think about it for atleast 3 months. Sometimes you might change your mind, but if you can really say you thought it was a good idea for 3 months straight, than you probably won't regret it later on.
I wanted a tatoo when I was 15, of a bass clef, i finally got one when i was 19, when i went to vegas(no I wasn't drunk =P)
Bass clef
I hope you get one that you will really enjoy later on