Help identifying fish

[Cooperwick]

I'm new to marine fish aquarium. I saw this fish at one of the big aquariums and couldn't identify it. I'd like to get one for my tank if possible but I don't know what it is. Looks like some kind of boxfish maybe. Can anyone identify it? If I posted this in the wrong forum let me know and I will move it.

 

[Labridaedicted]

I believe that is a Thornback Cowfish. Never seen anyone keeping one in a home aquarium, but if you can source one, they are feasible if you have a big tank. They can be pretty toxic if they get stressed out, though.