Valerie finds Finn's outfit to look something straight off of Saturday Night Fever when she first sees it, and she describes Jade demonstrating the Rabbit Talisman's power as turning into a mini version of the The Flash.
When Valerie swims frantically in the flooding Embarcadero Station, she compares the experience to being in close proximity to Jaws.
Valerie and Shendu's confrontation in the antepenultimate chapter has lines borrowed from the climax of Labyrinth.
The Stronger Evil
Valerie, who already compared her first visit to Section 13 to being in a Men in Black film in The Ultimate Evil, hums the theme song when she first returns there.
Valerie can't help but think of Jurassic Park when she enters the zoo where the resurrected Shendu has followed her friends. When she and Jade are later hiding from Drago in a school library, she mutters that no one had better start humming the theme.
Valerie mentions The Terminator when Jade assumes Drago to have a similar reason for coming to the present.
When reading the newspaper, Valerie comes across an article about homeless people spreading stories of gargoyles in New York.
Nat makes a reference to Star Wars by calling Tarakudo's telekinetic powers the Force and saying that she's not a Jedi.
Nat's last line in the 11th chapter ("We are in very serious trouble…") is a reference to The Mummy (1999) and the author's direct defiance of the 2017 version.
Nat and Valerie mention the spellsWingardium Leviosa and Petrificus Totalus in the 14th chapter.
Shendu showing Valerie his human disguise and his disappointment at her reaction are borrowed from The Ancient Magus' Bride.
Valerie is called Shendu's "Harley-Quinn rip off" by the burglars' leader in the 17th chapter.
A citation from The Bloody Chamber continues the recurrent habit from The Ultimate Evil to describe Shendu and Valerie's relationship.