Episode 17.4 of South Park is called "Goth Kids 3: Dawn of the Posers".
I would like to find episodes Goth Kids 1 and Goth Kids 2, but failing to do this. Are there such episodes at all?
As this Wikia page explains, this episode is a sequel to 2 other episodes where the Goths were featured most prominently: Raisins from season 7 (where Stan becomes a Goth) and The Ungroundable from season 12 (where Butters becomes a vampire wannabe). The title of this episode is probably a parody of Ice Age 3: Dawn of the Dinosaurs and maybe alludes to Dawn of the Dead (though that was the 2nd film in Romero's zombie series).