Musk also changed his user title to "Daddy DotCom." Hours later, Musk changed his user title back to "Elon Musk." Sunday was Father's Day in the U.S.
Tesla did not immediately respond to a request for comment.
The billionaire is only months removed from a settlement with the Securities and Exchange Commission regarding his Twitter use. The SEC alleged that in February, Musk broke the terms of a November penalty, following his notorious "funding secured" tweet about taking his car company private.
Musk's deal with the SEC requires a lawyer must approve any of his social media posts that may include material information about Tesla. Under the agreement, Musk agreed that he would not tweet about Tesla, finances, production numbers and other specific information without first getting a lawyer's approval. A federal judge approved the settlement in May.