Over the past year, the number of television series about American pack-rats hard been absurd (Hoarders, Animal Hoarders, Hoarding: Buried Alive...) The show took notice and worked hoarding into a ridiculous episode that had South Park invading each others dreams.
After Wendy decides that Stan has a hoarding problem, he's subjected to an embarrassing public cleaning-out of his school locker. Upon his realization that he may actually be a hoarder, he seeks advice from the school's guidance counselor. It turns out that Stan's not the only hoarder in school.
For various reasons, Mr. Mackey, Stan and an actual sheep hoarder are put into a deep trance in hopes of discovering the reasons behind their hoarding. Unfortunately, things go awry, and we're treated to a Christopher Nolan-like trek through Mr. Mackey's dreamstate. The main highlight of the episode (for me, at least) was the recurring gag that any time someone began to explain the process of inception, this one guy would stand behind and sing the Inception music.
Despite the lack of Cartman throughout the episode, we were still treated to an A+ Randy Marsh moment when he "goes under" and appears as a butterfly.