Hi,
I have a yellow tang. They get way too big for a 10 gallon tank and they need swimming room, so a 55 gallon minimum is recommended.* They are especially susceptible to saltwater ich, so you'll definitely have to quarantine for a few weeks before introducing in to the main tank.* They also need highly oxygenated water, either thru airstones or high surface agitation with power heads.
More info:
http://www.fishlore.com/Profiles-YellowTang.htm
If I recall the movie correctly, I think that Dory from the Nemo movie is a hippo tang... Not sure though
Yellow Tangs are one of my favorite saltwater fish - they are really beautiful and fun to keep.
Mike