southpark.wikia.com

XEDwP TIL Comedy Central originally wanted to remove Timmy from South Park due to the potential controversy over the inclusion of a mentally handicapped character. Matt Stone and Trey Parker pushed to keep the character on the basis that other children in the series treat him equally.
oBNVA TIL that Trey Parker and Matt Stone lost the Oscar for Best Song to Phil Collins in 1999. As a result they brutally satirized him in the episode “Timmy 2000.” They have him sing a parody of “You’ll Be In My Heart,” get booed off stage, and then had his Oscar shoved up his ass.
JY1e1 TIL that Kenny in South Park was based off of a childhood friend of Trey Parker's; his running gag of dying in most episodes was because he would skip school from time to time, only to show up days later.