Elon Musk has escalated his rivalry with Mark Zuckerberg in his latest tweets, calling the Meta co-founder a "cuck." Since Zuckerberg's Meta launched Threads, a text-based social media app to rival Musk's Twitter, the two billionaire businessmen have been exchanging jibes online. Some of these include Zuckerberg taking to Twitter for the first time in 11 years to post a Spider-Man meme, Musk challenging Zuckerberg to a cage fight and Twitter threatening Threads with a lawsuit. Sign up to our free Indy100 weekly newsletter Now, Musk has responded to a screenshot from Threads that shows a post from the official account of the fast-food chain Wendy’s that reads: "hey @zuck, you should go to space just to make him really mad lol." To which Zuckerberg replied with a crying laughing emoji. Though clearly, this didn't amuse Musk as he declared on Twitter in response: "Zuck is a cuck." And he didn't stop there, in a follow-up tweet suggested another contest - not a cage-fighting one this time but something more explicit: "I propose a literal d*** measuring contest," Musk tweeted, along with a ruler emoji. The Elon Musk parody account cracked a joke in response to the real Musk's latest tweets: "At this point, I can't keep track of which account I'm tweeting from." This is the same parody account that called Zuckerberg a "lizard boy," and caught the attention of the actual Elon Musk who responded: "So many people think this account is me," with the eyes emoji. Zuckerberg has yet to respond in this war of words, though clearly this feud is far from over... Elsewhere, what is Threads, Instagram's 'text-based' alternative to Twitter, Threads users issued warning over new social media app, and Elon Musk responds to parody account calling Mark Zuckerberg 'lizard boy'. Have your say in our news democracy. Click the upvote icon at the top of the page to help raise this article through the indy100 rankings.