https://www.theguardian.com/technology/2023/jun/22/mark-zuckerberg-elon-musk-cage-match

Zuckerberg has been competing in Brazilian jiu-jitsu; Musk has size on his side – and a move called ‘the Walrus’

In the red corner, the world’s richest person, and in the blue corner, the world’s richest millennial: Elon Musk and Mark Zuckerberg have agreed to a cage match, after Musk jokingly suggested the bout in response to efforts by Meta to launch a Twitter competitor.