Mr. Musk, the world’s richest man and the leader of Tesla and X, delivered a dark warning during an animated appearance at former President Donald J. Trump’s rally.

Elon Musk made a surprise appearance at Donald Trump’s rally in Pennsylvania, but it was his unexpected jump on stage that took social media by storm, inspiring a wave of memes.

One internet sleuth remembered a scene from Friends where Ross jumps up and down with Rachel and Pheobe when he believes he found a new apartment. Ross, played by David Schwimmer, is seen flailing his arms and screaming in a high-pitched tone.