US President Donald Trump gave a ceremonial farewell to Elon Musk in the Oval Office and presented him a golden key to the White House for his service. (Photo: X/WhiteHouse)

The Tesla CEO stepped down as the chief of the Department of Government Efficiency (DOGE). (Photo: X/WhiteHouse)

Musk was seen wearing a black T-shirt with the word "Dogefather" in white lettering and a black DOGE baseball cap. (Photo: X/WhiteHouse)