It's a Yellow Tang. These fish need a saltwater set up, the fish itself in terms of cost is just pennies compared to the hundreds, even thousands, you can spend on the set up it needs! Tangs are active, for one of these ideally you will need a tank over 55 gallons. And contrary to the film, it won't get obsessed with bubbles...
Keeping saltwater tanks is not for the faint-hearted nor for the poor!
If you're interested in keeping a saltwater tank, buy some books, join some of the MANY reef-keeping forums. Don't spontaneously buy a thing, do lots of research.