Elton John appears as a guest vocalist for Chef's song, in one of the earliest celebrity spoof appearances on the show. Trey Parker said many people thought it was the actual John singing because his impression was so accurate.
Comedy Central made Trey Parker and Matt Stone cut a scene in which Shelley sets Stan on fire the second time she beats him up to keep the show from coming under the same fire for showing dangerous acts that can easily be imitated as MTV's Beavis and Butt-Head (1993). Even though the scene is cut, the part where Stan is lying on top of a puddle of water as he's telling Shelley that someday he'll be bigger than her and she'll regret beating him hasn't been altered.
The subplot with Stan getting beat up by his sister Shelley came from Trey Parker's real-life experiences getting beat up as a child by his sister, also named Shelley, who is three years his elder. Parker said although his sister would later deny it, she regularly beat him up or locked him out of the house for hours; Parker stated that the scene when Stan says "You're my sister and I love you" in order to try to avoid a beating, but was subsequently beat even harder, was based on an actual experience with his sister. The scene in which Stan asks the giant mutant Stan to attack Shelley is based on Parker's childhood fantasy of having a larger version of himself beat up his sister. The resolution to the subplot, in which Shelley takes the blame for Stan's mistakes, and then beats up Stan when he tries to thank her, was also based on experiences Parker had when his sister would bail him out of trouble.
Trey Parker and Matt Stone intended to call this episode "An Elephant Fucks a Pig", but changed the title under pressure from Comedy Central.
When originally aired in Canada on Global, Mr. Garrison's line about genetic engineering being able to correct God's horrible mistakes, "like German people" was cut to remove the "like German people" part. However, this is uncut when aired on The Comedy Network.