In the "Seven Bons" gag arc, we see that Bon Bon's voice is always "changing" because she has a bunch of identical sisters, one of whom is a secret agent named "Bon-Bond". In the 100th episode "Slice of Life" (the title is even the same), Bon Bon being a secret agent turned out to be canon.
Older!Pound Cake's hairdo in Slice of Life bears more than a remote resemblance to Older!Pound Cake's hairdo in the show's finale. In both cases, he grew that one lock up front to almost Leningrad Cowboys size.
