Cartman’s joke was basically a prank that made Alexa and Google Home repeat or react to crude, absurd commands, which is why the episode set off real devices in some viewers’ homes.

What he said

  • The gag involved Cartman triggering the assistants with disgusting or offensive phrases, rather than one single famous line.
  • One widely reported line from the episode’s Alexa gag was: “Suck my big balls and hairy butthole”.
  • The point of the scene was to make the smart speakers respond to Cartman’s nonsense and to mock how easily they could be activated.

Why people noticed

  • The episode caused actual Amazon Echo and Google Home devices to respond in viewers’ homes, which turned the joke into a real-world interruption.
  • Reports described it as a Season 21 premiere prank centered on Cartman and the smart assistants.

Context

  • This was part of South Park’s recurring style of pushing a joke until it spills out of the screen and into the audience’s living room.
  • The scene was especially memorable because it blended the show’s crude humor with a tech-device gag that many viewers experienced firsthand.

TL;DR: Cartman said crude stuff to trigger Alexa and Google Home, and the best-known quoted line tied to the gag is “Suck my big balls and hairy butthole”.