Kenny is a third, later fourth-grade student who commonly has extraordinary experiences not typical of conventional small-town life in his hometown of South Park, Colorado, where he lives with his poverty-stricken family. Kenny is animated by computer to look as he did in the show's original method of cutout animation. He also appears in the 1999 full-length feature film South Park: Bigger, Longer & Uncut, in which his true appearance and voice was first revealed, and various South Park merchandise.
In a running gag most prevalent during the first five seasons of the series, Kenny would suffer an excruciating death before returning alive and well in the next episode with little or no explanation given. Stan would frequently use the catchphrase "Oh, my God! They killed Kenny!", followed by Kyle exclaiming "...You bastards!" Since the show began its sixth season in 2002, the practice of killing Kenny has been seldom used by the show's creators. Various episodes have set up the gag, sometimes presenting a number of explanations for Kenny's unacknowledged reappearances.
Kenny's superheroalter ego, Mysterion, first appeared in the Season 13 episode "The Coon", as a rival to Eric Cartman's eponymous superhero alter ego. He unmasks himself at the end of the episode, but his identity is left intentionally ambiguous. He is not revealed to be Kenny until the Season 14 episode "Mysterion Rises", the character's third appearance as part of a story arc.