- For other uses, see John (disambiguation).
Jonathan "John" Hansen, also known as John 'Nancy' Hansen, voiced Mr. Slave, the former boyfriend of and assistant to Mr. Garrison. He was also on the production team as a post-production supervisor and now is on the team as a production supervisor for more recent episodes.
- "Asspen" - Singing "Take on Me" during the end credits.
- "Butters' Very Own Episode" - Heard in the background in the steam room.
- "The Death Camp of Tolerance" - Debut appearance.
- "South Park is Gay!" - Helps Herbert Garrison and Kyle Broflovski in their atempt to kill the "Queer Eye For The Staight Guy" people.
- "Quest for Ratings" - Seen buying cough medicine at the pharmacy with Mr. Garrison.
- "Stupid Spoiled Whore Video Playset" - Wendy Testaburger asks for his help becoming a whore, later prompting him to have a "whore off" with Paris Hilton.
- "Mr. Garrison's Fancy New Vagina" - Breaks up with Garrison after his sex change operation.
- "Follow That Egg!" - Becomes engaged with Big Gay Al and later gets married.
- "The Ring" - Seen briefly at the Jonas Brothers concert.
- "The F Word" - Seen with Big Gay Al lobbying to stop the overuse of the word "fag". Then later seen saving the boys, as they try to change the word's meaning.
- "201" - (cameo) Proclaimed the arrival of Jesus Christ and the Super Best Friends (Group).
- "Not Funny" - Seen convincing President Garrison to bomb Denmark.