This episode continues the storyline from the season one episode, "Cartman's Mom Is a Dirty Slut".
This episode was originally to air on April 1, 1998, four weeks after "Cartman's Mom is a Dirty Slut" was first broadcast, but instead of continuing the storyline from "Cartman's Mom is a Dirty Slut", Parker and co-creator Matt Stone made an episode regarding the South Park minor characters Terrance and Philip, called Terrance and Phillip in Not Without My Anus", as an April Fool's Day prank on viewers of the show.
Meanwhile, the town of South Park experiences a massive blizzard.
The episode premiered after the season premiere "Terrance and Phillip in Not Without My Anus" was aired in its place three weeks earlier as an April Fools' Day prank.
They choose to eat Eric Roberts first, and later the rest of the production crew. Once Kenny gets to the generator, he discovers that there is no wire connecting the cords, so he decides to make the connection himself to restore the electricity, fatally electrocuting himself in the process.
Thanks to his brave deed, the power is back on at the hospital so Mephesto can survive.
After revealing his shooter was his brother (who apparently tries to shoot him often), he gathers everyone in the emergency room for a surprising revelation of Cartman's father: his mother Liane.
The group is shocked upon hearing this and Mephesto explains that Liane is a hermaphrodite, someone with both male and female genitals.
On April 27, 1999, "Cartman's Mom Is Still a Dirty Slut" was released on the "South Park: Volume 7" VHS tape which also contained "Cartman's Mom is a Dirty Slut", in a third series of South Park home video releases.
Volume 7 was sold along with Volume 8, which contained "Chickenlover" and "Ike's Wee Wee", and Volume 9, which contained "Conjoined Fetus Lady" and "The Mexican Staring Frog of Southern Sri Lanka".
Written by series co-creator Trey Parker and David Goodman, and also directed by Trey Parker, "Cartman's Mom Is Still a Dirty Slut" was rated TV-MA in the United States and 12 in the United Kingdom.