Around 12AM ET last night, Twitter owner Elon Musk started tweeting — and did so for hours — about the Twitter rebrand to X, the one-letter name he’s used repeatedly in company and product names forever. It started with a tweet saying “soon we shall bid adieu to the twitter brand and, gradually, all the birds,” followed by a second tweet adding that “if a good enough X logo is posted tonight, we’ll make go live worldwide tomorrow.”

Musk then, over the next several hours, gestured at the change in between other posts and replies, tweeting things like “Deus X,” or replying to other users talking about it. At one point, he joined a Twitter Spaces session called “No one talk until we summon Elon Musk,” and sat silently for almost an hour before unmuting and confirming he would be changing Twitter’s logo tomorrow, adding “we’re cutting the Twitter logo from the building with blowtorches.”

The letter “X” has been on just about everything Musk has touched for the last two-plus decades. X.com was the original name for Paypal; it’s in his SpaceX company name; it’s in the name for the Tesla SUV; and he has said he wants to turn Twitter into “X, the everything app.” Maybe that’s what he’ll do with the X.com domain name he bought back from Paypal in 2017.

Finally rebranding the site will be the clearest declaration yet that this is no longer the same social network that it was before Musk purchased it last year. But it’s far from the only change in the Musk era of Twitter.

We have reached out to Twitter for comment. An auto reply said, “We’ll get back to you soon.”