Alien Blood: The worm bleeds orange blood when Rayla slashes it.
And I Must Scream: When Runaan won't tell Viren what a magic mirror does, Viren uses dark magic to trap Runaan inside of a coin. He is implied to have done this before as well.
Chirping Crickets: The group makes various jokes about how the Cursed Caldera doesn't seem very cursed and that so far the scariest thing they've seen is an angry cricket. Callum's quip, however, of "recognizing the unmistakable topography of Mount Monotonous" gets no response other than the cricket's chirping. A bit later, Bait eats the cricket.
Death Mountain: The Cursed Caldera is an extinct volcano rising high above its surrounding peaks, dominating the skyline as a looming presence on the horizon. Its sides are crossed by deep ravines, precarious paths and steep cliffs, dotted with dead trees and infested with horrifying monsters. The people who live in the nearby village are terrified of it and won't go anywhere near it, even though a miraculous healer is said to live at the mountain's peak. In truth, the monsters are nothing but illusions conjured up by the peak's resident, who is simply a skilled illusionist rather than a healer.
Enemy Rising Behind: When the worm monster attacks for the second time, it rises behind the group while they talk about Tempting Fate.
"Eureka!" Moment: When Rayla realizes that Claudia was actually shouting "Fulminis!", the Draconic word needed to cast the lightning spell, and not "fool" as Callum suspected since he only heard the first syllable.
Fate Worse than Death: Since Moonshadow assassins like Runaan do not fear death, Viren concludes that the only way to get Runaan to talk would be to present an alternative worse than death.
Flower Mouth: In combination with Lamprey Mouth. The worm features outer jaw flaps that open to a circular mouth surrounded by sharp teeth.
Run or Die: Callum's advice to the group when the worm monster attacks.
Super-Persistent Predator: The worm is very patient to wait for the group to come down from the tree and the rock. Even though Rayla herself points out that they do not have much blood to begin with.
Tempting Fate: Discussed Trope. Rayla cautions not to be too sure that the worm is gone since Irony is sure to bite them for it. Just as Callum mentions that that's the sort of thing that happens in stories, the worm attacks.