Which South Park character is the son of Satan?

The South Park character who is the son of Satan is Damien. He appears as a new student in the first-season episode “Damien,” where his father sends him to South Park to locate Jesus and arrange a final battle between good and evil.

Damien is introduced as a powerful and frightening child. He throws Cartman’s desk through a window, transforms Kenny into a duck-billed platypus, and sets the school playground on fire. The townspeople focus on the planned boxing match between Satan and Jesus, placing bets based largely on Satan’s enormous size and intimidating appearance.

The episode first aired on February 4, 1998, and uses Damien’s supernatural abilities for both horror parody and comedy. A common mix-up is identifying Cartman as Satan’s son because Cartman is central to the episode and often behaves villainously. Cartman is not Damien’s parent or sibling; Damien’s defining relationship is that he is Satan’s child. Satan also reveals that he intentionally loses the fight after betting on Jesus, allowing him to win the town’s money.