The incantation Mandy recites at the blackboard is loosely based on a small portion of the lyric to the 1953 James 'Sugar Boy' Crawford song, "Jock-A-Mo"; also known as "Iko Iko" by The Dixie Cups (1965). The historically litigious nature of the song might explain why it's misspelled, mispronounced and more well disguised than most cultural references written into this show.
In the scene where Nergal Junior and Irwin get in a punch throwing contest, Kool-Aid Man (the mascot for Kool-Aid brand flavored drink mix), makes an appearance.
The music for the Valentine's Day Dance played during the credits is a cleverly disguised tribute to the song "Billie Jean" (1982), by Michael Jackson.