What is up with Elon Musk and "Adrien"? Who is that?

Okay, so I've seen Elon having fake accounts before- like the weird thing a year or two ago pretending to be his kid? I don't know, it was weird.

But today's update has been someone named Adrien talking on Twitter, and people suggesting it's Elon using a voice changer to pretend to be someone else? Who's Adrien and what's he been saying?

https://x.com/JohnsonThought1/status/1872682651469193416