In the Moon Cliffs in Khrysalis, there's a quest where some type of storage area was being burned down by some fire elementals, who say, "Burn, baby burn! Honeymill inferno! Burn, baby burn! Burn it all down!", a pretty obvious reference to to the song Disco Inferno by The Trammps.
I've checked this entire thread and I've seen someone mention it but not in detail.
In The Vault of Ice, the three defenders of the fang are based of The Weird Sisters, (or The Three Witches) in Shakespeare's play, Macbeth. Just read what they say.
Play Quote: Fair is foul, and foul is fair Hover through the fog and filthy air. Protector of the Fang: "Fair is foul, and foul is fair. Try and take this Fang if you so dare..."
Play Quote: (couldn't find the quote in the book that this was referencing. if anyone would like to post it for me, that would be greatly appreciated.) Defender of the Fang: "'Tis the Fang you've come to claim as your own? Tamper with me, little Wizard and I'll turn you to stone!"
Play Quote: Show his eyes and grieve his heart. Come like shadows; so depart! Guardian of the Fang: "Show your eyes, and grieve with your heart. Come to the shadows, and prepare to depart!"