CM Punk has made as many fans an enemies (well, maybe that's a bit of a harsh word) in announcing his transition from the world of professional wrestling to mixed martial arts. And while some fighters have shown their support, others have criticized the move, complaining that a man with no professional MMA fights should not be allowed to star at the top. Then there are the fighters who have gone a little further, and outright called Punk out. Now, callouts happen all the time in the MMA world. It's a way to get your name in the press, get the attention of a fight promotion's match-makers, and lock on to your next opponent. A good callout will make fans want to see the fight in question. To date, nothing has been made official about CM Punk's first opponent in the octagon. And for good reason: he has months of training ahead of him, and no firm debut date set. On the other hand, that hasn't stopped a handful of fighters from calling him out - some no doubt just wanting a piece of the limelight, others unhappy he's even being given a shot in the UFC. Whoever does wind up booked against Punk for his first fight stands to gain a huge career boost - maybe. Anyone with experience will actually be expected to win, so if they lose, their career will actually take a heavy blow. That said, a win will get them tons of time in the spotlight, so in that sense, the CM Punk lottery may be worth it. With that said lets take a look at six fighters who have already called out CM Punk!