Identify this breed of fish?

[spaceout]

Looks like I’m putting him in his own tank or with my other big aggressive boys, are they worth much because the owner of the store didn’t know what it was.

As a fully grown adult to the right person it might sell for a decent amount, but they're common enough they're not particularly valuable. Due to their temperament they're not the easiest fish to get rid of.

 

[twentyleagues]

Oh dear. This is the OP's first post and he's just been told all his fish barring one are probably going to be dead within a year!

That's a fantastic welcoming present.

Yo! We keeps it realz. Hello be fo sukaz!
Lol
Welcome! Your fish will soon be a murderer! Have a nice day.