SpaceX founder Elon Musk appeared as a special guest at former President Donald Trump's rally in Butler, Pennsylvania, on Saturday.

Donning a black "Make America Great Again" hat, the billionaire joined the former president on stage and started jumping near the podium to amp up the crowd. The rally was held at Butler Farm Show, the venue where Trump survived an assassination attempt in July.

"The true test of someone's character is how they behave under fire. We had one president who could not climb a flight of stairs and another who is fist pumping after getting shot," Musk said during his speech, chanting, "Fight, fight, fight."

He continued, "This is a must win situation."

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Social media reacts to Elon Musk's speech

Musk, the owner of X, has used the social media platform formerly known as Twitter to call Trump the best candidate to win the upcoming presidential election. In August, he hosted a conversation with Trump riddled with technical glitches, marking the former president's return to the platform.

Following the July 13 attack against Trump, Musk posted: "I fully endorse President Trump and hope for his rapid recovery."

During his speech over the weekend, Musk referred to himself as "dark MAGA." His appearance garnered mixed reactions on social media, with some people taking digs at the billionaire entrepreneur while others praised him.

"I'm so happy I lived long enough to see Elon Musk become Trump's hype man," comedian Chrissie Mayr wrote on X.

"Elon came out jumping and more energetic than a fully charged Tesla battery," another person said. "This will go down as the greatest Trump rally in history."

Other people labeled him "pure cringe."

"How do we get Elon musk to stop doing that little jump," an X user asked.

Another person shared a video of Musk jumping "into orbit."

Other guests who appeared at the rally included Trump's son, Eric, his running mate, Ohio Sen. JD Vance and singer Lee Greenwood.

Taylor Ardrey is a news reporter for USA TODAY. You can reach her at [email protected].