"Damien" received generally positive reviews and was viewed by 3.2 million households when it was first broadcast, making it the highest rated cable program the week it aired. The episode marked the first appearance of Satan, who would become a recurring "South Park" character, as well as the character of Damien himself, who was inspired by the antagonist of the 1976 horror film "The Omen". Parker and Stone also said the episode introduced several key characteristics of the Cartman character that have endured throughout the rest of the series. Michael Buffer, the boxing ring announcer best known for the catchphrase "Let's get ready to rumble!", makes a guest appearance as himself.