The battle of the Tech Titans has taken a surreal twist: Elon Musk and Mark Zuckerberg have agreed to fight each other in a cage match.
Mr Musk seemingly started the tough talk when he posted on Twitter that he would be “up for a cage match” against his rival.
The Meta chief executive replied on Instagram, telling Mr Musk to “send me location”.
“Vegas Octagon,” replied Mr Musk, who turns 52 this month.
The Octagon in Las Vegas is used for Ultimate Fighting Championship events.
“I have this great move that I call 'The Walrus', where I just lie on top of my opponent & do nothing,” Mr Musk tweeted later.
Mr Zuckerberg is a prize-winning jiu-jitsu enthusiast but Mr Musk, who is 6 feet, 1.5 inches tall (about 1.87 metres) would have the size advantage over Mr Zuckerberg in the ring, with the Facebook co-founder measuring 5 feet, 7 inches (1.7 metres).
Mr Musk has also talked about being in “real hardcore street fights” when he was growing up in South Africa, The Verge reported.
After completing his $44 billion takeover of Twitter in October, Mr Musk made a series of changes that led to a turbulent time for the company.
Within the first two weeks, he laid off half of the staff and fired the company's former chief executive as well as other senior leaders.
His ownership of the social media platform has been criticised over changes including paid subscriptions for verification status, a “For You” newsfeed and the reinstatement of controversial accounts such as that of former US president Donald Trump.