CM Punk: Blasted By UFC Fighter ... You're a Joke!!!

CM Punk doesn't deserve to be in the UFC -- and will likely get his ass beat in his UFC debut because he's not a real fighter ... so says UFC fighter Lorenz Larkin.

Larkin has been a pro fighter since 2009 -- and essentially lays out why allowing the former WWE superstar in the Octagon is an INSULT to the sport.

You gotta watch this clip ... Larkin throws the SHADE OF THE YEAR -- and says he'd be worried for Punk's life if the UFC ever allowed the two to square off.

"The UFC doesn't have enough insurance for what I'd do to him."

FYI, Punk makes his debut at UFC 203 in September -- we'll see if Larkin's right.