Floyd Mayweather

Floyd Mayweather is now in a feud with Conor McGregor, meaning arguably the world's best boxer and best UFC fighter are using words to attack each other. In November, McGregor said he wanted $100 million to box Mayweather. Earlier this week, Mayweather said he would "slap the s***" out of McGregor next time he sees the Ireland native.

On Wednesday night, Mayweather posted a video on Instagram of McGregor's last loss, which came by submission (rear-naked choke) to Nate Diaz in UFC 196 on March 5. McGregor, who is 21-3 in his career, beat Diaz in an August rematch and defeated Eddie Alvarez in November.

Mayweather is offering $10,000 to the fan who writes the best caption for the clip:

CAPTION THIS! Best caption wins $10,000.00. The winner will be announced on Monday, Dec 19. Stay tuned ! #TMT

A video posted by Floyd Mayweather (@floydmayweather) on

Folks, you have until Dec. 19 before Mayweather crowns a winner. The boxer has 13.9 million followers and as of Thursday morning, the post already had over 138,000 comments in ten hours. Someone on The Money Team is about to read a lot of comments.

Mayweather has not fought since Sept. 12, 2015, standing by his word that he would retire after defeating Andre Berto and reaching 49-0 (so for the record, McGregor has no videos of Mayweather losing to come back with). The idea of Mayweather and McGregor actually ever fighting in a boxing-MMA crossover is pretty ridiculous, but it is fun to think about. Or comment on for $10,000.

-- Follow Jeff Eisenband on Twitter @JeffEisenband. Like Jeff Eisenband on Facebook.