Famed boxer Floyd Mayweather has made a habit of drawing headlines for his wild antics and for at times acting unnecessarily confrontational. The trend continued Wednesday afternoon, when he took to Twitter to needle his last opponent, Conor McGregor.

True to form, McGregor answered Mayweather's Twitter posting with a posting of his own.

Mayweather's Twitter posting was in response to a late-November SB Nation headline about an incident at McGregor’s home country of Ireland. The UFC star, who infamously challenged Mayweather to a comeback boxing match in 2017, reportedly punched an Irish mafia associate in a bar and racked up a bounty, per SB Nation. Though the incident occurred more than a month ago, Mayweather said McGregor would “start off the new year with a bang,” followed by a knife emoji, two hammer emojis, a bomb emoji and a coffin emoji.

Mayweather and McGregor met in the boxing ring in an August pay-per-view fight that was largely thought of as a money-making scheme rather than a competitive prize bout. Though McGregor lasted until the 10th round, the fight ended as most expected, with the all-time great boxer winning by technical knockout over a mixed-martial arts fighter who never had a professional boxing fight.

Theatrics, trash talk and race-baiting were heavily on display during their promotional tour. Notably, McGregor came under fire for calling Mayweather “boy” and saying black characters in “Rocky 3” were “dancing monkeys.”

Mayweather also came under fire Wednesday for what people felt were ignorant comments about the #MeToo movement, which has sought to increase awareness of instances of sexual harassment and assault carried out by powerful men. In December 2011, Mayweather was sentenced to jail for battery against his former girlfriend Josie Harris.