The SpaceX CEO appeared to mimic Trump's nickname for Biden.
SpaceX completed its first ever all-civilian spaceflight last week with the successful splashdown mission of its Inspiration4 mission.
Soon after, Elon Musk and the company received praises and congratulations from NASA Administrator Bill Nelson as well as spaceflight industry competitors like Blue Origin CEO Jeff Bezos.
Musk took offense at President Biden's inability to offer a congratulation on Twitter.
Musk mocked Biden Sunday afternoon, after a Twitter user called out President Obama for not acknowledging the success of the missions or the amount raised for St. Jude Childrens Research Hospital.
Musk responded, "He's still asleep," in reference to Trump's nickname for his successor, Sleepy Joe.
Musk isn't the only one to take a dig at Biden. He responded to a meme last week depicting the union United Auto Workers, a parasitic alien, as a response to Biden's frustration over a new law supporting unionized automakers.
Feed the Animals
SpaceX enjoys a good relationship with the federal government. CNBC points out that the federal government has given many contracts to the private spaceflight company. An uninformed tweet will not change this, as SpaceX has been able to successfully launch missions to the International Space Station multiple times and is NASA's preferred company to build a Moon lander.
CNBC reached out to the White House for comment but they did not respond. If we are to speculate, Biden's spokesperson was likely too busy looking at the camera.
READ MORE: Elon Musk mocks President Biden after SpaceX completes first all-civilian mission [CNBC]
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