Conor McGregor Calls Jake Paul 'Little Dweeb Of A Thing,' Paul Claps Back

11:30 AM PT -- Jake Paul was asked about Conor McGregor's comment during his own press conference just minutes ago ... and he went OFF on the UFC superstar.

Paul said he's going to embarrass the entire BKFC with what goes down with Mike Perry on Saturday ... calling the promotion's athletes "brawler, idiot, street fighter dudes."

Paul also accused McGregor of ducking him ... saying the dude needs to stay off the drugs and get back to training -- and then maybe they can talk about booking a fight after getting a few wins under his belt.

Conor McGregor took aim at Jake Paul ahead of his boxing match against "Platinum" Mike Perry ... calling the YouTuber-turned-fighter a "little dweeb of a thing."

Notorious unloaded the diss during the Bare Knuckle Fighting Championship press conference at the Hard Rock Hotel in Marbella, Spain on Thursday ... when he was praising Perry's success with the promotion and what he's been able to do for his career.

"Look at what has happened to Michael Perry, one of our big stars here," McGregor -- who recently joined BKFC ownership -- said. "'The King of Violence,' he titles himself."

"He's had such a rise in the sport. Now he's up against a little dweeb of a thing in a fight this weekend. And, we're all rooting for him."

Of course, McGregor was referencing the big fight between Paul and Perry going down in Tampa on Saturday ... which was initially supposed to be a showdown with Mike Tyson before it was delayed due to the boxing legend's recent medical issues.

McGregor also addressed his own career ... saying after he fulfills his next two fights with UFC, he wants to take a stab at the BKFC talent.

Paul has yet to respond to McGregor ... but it's just a matter of time.