Billionaire entrepreneur Elon Musk has been ramping up his criticism of President Joe Biden, and on Thursday he called the president a “damp sock puppet in human form.” Burn. Musk was responding to the fact that Biden left out Tesla in a discussion of domestic electric vehicle production.

“I meant it when I said the future was going to be made right here in America. Companies like GM and Ford are building more electric vehicles here at home than ever before” tweeted Biden on Wednesday.

In a slew of posts, Musk responded to the President’s tweet which included video of him speaking with General Motors Chair and CEO Mary Barra. In the video, the two discussed the company’s $7 billion investment into manufacturing electric vehicles and battery cells in Michigan, reports Business Insider.

“Starts with a T, Ends with an A, ESL in the middle” tweeted Musk. When one Twitter user commented on Biden’s video, Musk jumped in with the discussion with the insult. “Madness has taken national proportions…Shame on Joe Biden and Mary Barra for this lie, it’s so insignificant to be like that” tweeted the user.

In response to the comment, Musk tweeted, “Biden is a damp sock puppet in human form” and of course, added a sock emoji.

President Bide was not the only target of Musk’s biting tongue. When one Twitter user posted a screenshot of a CNBC report about GM’s bid to overtake Tesla in EV sales by 2025, despite having only sold 26 electric vehicles in the last quarter, Musk wrote “they appear to have some room for improvement.”

Business Insider notes that Musk’s attitude towards President Biden and his administration has drastically changed in his first year of presidency. Just after Biden’s inauguration, Musk told Fortune he was “super fired up that the new administration is focused on climate.”

Since, Musk has “torched the centerpiece of the president’s domestic agenda, a climate and spending plan known as Build Back Better, mused that Biden is ‘controlled by unions,’ and joked that Biden was ‘still sleeping’ when the White House didn’t remark on Space X’s historic, private space flight” writes Business Insider.